PROVIDENCE, R.I. — Arkansas basketball coach John Calipari said earlier this week he is back to his roots in an underdog role.

His team embraced that character Thursday night.

The 10th-seeded Razorbacks wiped away a late deficit and upended seventh-seeded Kansas 79-72 in a thriller at the first round of the NCAA Tournament at Amica Mutual Pavilion.

Arkansas (21-13) will play St. John's (31-4) on Saturday at 1:40 p.m. Central in the second round. The second-seeded Red Storm defeated Omaha 83-53 on Thursday night.

“This was a good one,” Calipari said. “That was an NCAA Tournament game — two teams battling it out, making shots, making plays, and we got away from them at the very end.”

Kansas (21-13) lost in the first round for only the third time in the last 44 years. It was the Jayhawks’ first loss in the round since they were upset 77-73 by 13th-seeded Bradley in 2006.

Arkansas eliminated Kansas for the second time in three seasons. The Razorbacks defeated the top-seeded Jayhawks 72-71 in the second round in 2023 when Self was unavailable following a heart procedure.

“If I'm not mistaken, no matter what you do in life, there's going to be some ups and downs,” Kansas coach Bill Self said. “And we just haven't had very many downs, to be honest with you. The last two years, we were such a beat up team at the end, we probably didn't have much of a chance with our injuries….This year we don't have that excuse.

“This year our roster was good enough to be competitive, but it probably wasn't the roster it needed to be to be talked about in a way that the best teams in America are talked about.”

Arkansas blew an 11-point lead in the second half and fell behind 67-64 with 4:55 remaining, but the Razorbacks closed the game on a 15-5 run. It coincided with Kansas senior forward KJ Adams exiting the game with an injury with 3:10 to play.

“I would have to go back and look at it, but he's got an Achilles injury,” Self said. “We're hoping for the best tomorrow. I'm not sure it's going to be great news, though. He got the rebound, came out on it. I think we had the numbers and then he went down….That’s a pretty big blow.”

Adams scored 13 points in 32 minutes and was key to the Jayhawks' zone that gave the Razorbacks trouble after halftime.

Nelly Davis, a Florida Atlantic transfer, entered Thursday having played in six NCAA Tournament games, including at the 2023 Final Four. His experience on the big stage was key for an Arkansas team with an 8-man rotation, half of which had never played in a postseason game.

Davis made a three-pointer with 1:47 remaining that gave Arkansas a 71-67 lead, then put the game out of reach with 4 of 4 free throws in the final minute. It was part of an 18-point performance for Davis.

“I was really just trying to take in the moment and try to keep the guys on the right track so we could win,” Davis said. “We knew they were going to go on a run, so we came out, we held our head down and then we just kept fighting.”

Arkansas also leaned on the postseason experience of senior forward Jonas Aidoo, who started for the first time since a 65-62 loss to Oklahoma on Jan. 25 in Fayetteville. The Tennessee transfer scored a team-high 22 points in 39 minutes.

“I knew it was going to be a big matchup from the jump,” Aidoo said. “I had to help the team out.”

Kansas used different zone defenses to claw back from a 55-44 deficit with 17:12 remaining. Arkansas was disrupted by the looks it saw and combined turnovers with cold three-point shooting (2 of 13) after halftime.

“Gutted it out,” Calipari said. “They went zone. We ended up shooting too many jumpers. [Kansas] had to do some different things — went a little triangle-and-2, also. [It] screwed us up a little bit.

“The kids fought. Nelly makes a shot, makes a couple free throws. Jonas makes free throws. [It] took us three times to get it in [on a late inbounds pass that required two timeouts]. I don't care. We won.”

The game was a series resumption for the two Hall of Fame coaches.

Calipari and Self entered Thursday tied for the most active NCAA Tournament victories among coaches with 57 apiece. Calipari took a lead that will stand until at least next year.

It was also an NCAA Tournament rubber match of sorts for Calipari and Self, who had only met in the tournament’s championship prior to this year. They had a friendly greeting before tipoff with back pats and smiles, but just a quick word in the postgame handshake line.

Calipari improved to 2-1 against Self in the postseason.

Self and the Jayhawks defeated Calipari-coached Memphis 75-68 in overtime of the 2008 national title game. Four years later, Calipari-coached Kentucky took down Kansas 67-59 for the 2012 championship.

“Where we are, be at peace,” Calipari said. “Don't worry about where I am in the past. It didn't have any bearing on what I do right now. The NCAA Tournament, talking about wins, it doesn't matter. National titles, none of it matters.

“It's this team [and] trying to get us better, but it doesn't work unless you have good guys. And we have a bunch of good guys.”

Aidoo, 6-11, had the early task of trying to limit Kansas All-America big man Hunter Dickinson, 7-2, who entered the matchup with 4 consecutive double-doubles.

With the two other Arkansas bigs — Trevon Brazile and Zvonimir Ivisic — in foul trouble before halftime, Aidoo was on the floor for nearly the entire game. Dickinson was held to 11 points, all scored in the first half, on 4-of-13 shooting. It was his fewest points scored since he scored 6 during a 74-57 loss at Iowa State on Jan. 15.

Kansas set the tone on its first few possessions that it was going to try and play through its big man. Dickinson took 4 of his team’s first 5 shots en route to an 11-point half.

“He's one of their go-to guys and he gets a lot of players run for him,” Aidoo said. “I was just being physical, just trying to wall up and make him finish over [the top], and try and make him speed up with the ball.”

Self called a timeout after an easy make inside by Aidoo on a feed from Karter Knox. The bucket put Arkansas ahead 9-5 with 17:17 left in the first half, and Self shouted at Adams coming to the bench, “You just gave up 4 points, KJ, wake up!”

Arkansas took its largest lead of the half, 12-5 on a three-point play by D.J. Wagner, but the Jayhawks responded and tied the game 14-14 with a Zeke Mayo three-pointer followed by a steal and score from Mayo. It was among 7 ties in a period that also had 8 lead changes.

Mayo sizzled from distance before halftime and went 3 for 3. His second three-pointer was part of a 14-4 run that put Kansas ahead 19-16 with 11:13 to play. Kansas shot 6 of 11 from three-point range in the half.

Arkansas freshman guard Boogie Fland returned to action for the first time since an 83-65 loss Jan. 18 at Missouri. He missed 15 games after surgery to repair his right thumb’s ulnar collateral ligament Jan. 22.

He checked in for the first time with 13:03 remaining in the half. Fland tried to dunk on a breakaway steal late in the first half, but his shot was blocked, and he hit the floor hard. It was a sign the freshman was going to play aggressive and not be worried about his thumb.

“I'm just coming out here trying to do whatever it takes to win,” Fland said.

Fland finished the game with 6 points, 3 assists and 3 steals in 24 minutes.

“'I’m just happy to be out there,” Fland said. “And happy to be still dancing in March.”

The teams traded punches in a back-and-forth, high-scoring first half, but Arkansas created some separation before intermission with a three-pointer by Davis and jumpers in the paint from Aidoo and Wagner.

Arkansas took a 47-44 lead into halftime and improved its record to 39-8 in NCAA Tournament games it has led at halftime. According to HogStats.com, it was the first time since the 1994 national semifinal against Arizona that both the Razorbacks and their opponent scored 40-plus points in the first half.

The high-scoring first half was a bit of a surprise for a pair of teams that entered Thursday ranked in the top 18 nationally in adjusted defensive efficiency, and outside of the top 45 in adjusted offensive efficiency by KenPom.

The Razorbacks came out firing to start the second half with back-to-back makes inside by Aidoo and Knox, plus a deep, pull-up three from Davis. Self called a timeout with Kansas facing its largest deficit yet at 54-44 with 17:44 remaining after the three.

Arkansas went nearly 16 minutes before hitting another three-pointer — the clutch make by Davis with 1:47 left.

“I thought we tried really hard and the zone kind of gave us a chance there in the second half,” Self said. “But we got off to terrible starts to start the game and to start the second half.”

Kansas scored its first points of the second half on a three by Mayo with 16:25 left that drew the Jayhawks within 55-47 at the first media timeout. It was the onset of an 11-4 run that trimmed the deficit to 59-55.

Brazile fought to counter the Kansas run with intensity on the glass. The only points for the Razorbacks during the sequence were put-back makes from the 6-10 redshirt junior.

Brazile played 19 minutes in the second half and 27 overall. He finished with 11 points and 12 rebounds.

“They went to that zone, and I had a guard on me most of the time they were in that zone,” Brazile said. “Every time a shot would go up, I know the guard can't stay in front of me. I was just running to the rim and the ball was coming my way.”

Arkansas grew its lead to 62-55, but the Jayhawks clawed back with a steal and score by Dajuan Harris and big alley-oop dunk from Flory Bidunga cut their deficit to 62-61 with 7:31 left to play.

Harris had a big second half for the Jayhawks. He scored all 8 of his points after halftime and had 2 steals.

Brazile threw down a dunk off an out-of-bounds lob to extend the lead to 64-61. Not long after, the Jayhawks took a 65-64 lead on a jumper by AJ Storr with 5:43 left. It was their first advantage since the first half.

With the Jayhawks leading 67-64, Adams hit the floor hard on a loose ball. He was helped off the court with the assistance of trainers.

Fland got a steal and score to get Arkansas within 67-66 before a steal by Aidoo. The forward was fouled by Storr and went to the free throw line for a 1-and-1. The 60% foul shooter made both to give the Razorbacks a 68-67 lead with 2:14 left.

After a steal by Wagner, the Razorbacks went up 71-67 on the three by Davis with 1:43 remaining.

“I yelled at him, 'Shoot the ball!'” Calipari said.

Arkansas extended its lead to 75-69 with 21 seconds left with free throws from Davis and Wagner.

“We did a lot of the damage ourselves, but their length bothered us all night long,” Self said. “We had open passes and couldn't pass over them and they got steals or deflections off of plays that could potentially be layups for us.”

Rylan Griffin hit a three for Kansas to pull within 75-72 with 13 seconds left, but from there Arkansas made game-clinching free throws.

The makes did not come without drama. Arkansas had to burn two timeouts to make sure Fland could get a baseline inbounds pass in without a turnover. Out of the last timeout, Wagner passed out of bounds to Fland, who got the ball into Davis.

“You know what we didn't do? We didn't turn it over,” Calipari said. “It took our third out-of-bounds play to get it in. That's fine.”

The Razorbacks improved to 9-5 in their last 14 games after beginning SEC play 0-5.

The season began and ended for the Jayhawks with losses to Arkansas. Ranked No. 1 in the preseason AP poll, Kansas lost Oct. 25 in a preseason charity exhibition at Bud Walton Arena. Both teams were missing key players in the game the Razorbacks won 85-69.

The Razorbacks received big performances from their two postseason veterans, Aidoo and Davis, a duo that combined for 40 points.

Although the Kansas zone gave Arkansas fits, the Razorbacks found ways to generate offense when it mattered most. A steal and score by Fland started a game-deciding 7-0 run in the late stages. The injury to Adams seemed to be a turning point.

Aidoo became the first Arkansas player to ever record minimums of 22 points, 3 blocks and 3 steals in an NCAA Tournament game.

It continued his strong, late-season form. Aidoo has scored at least 14 points in the team’s last four games.