LAWRENCE, Kansas — Kansas and Darryn Peterson left no doubt for a half Saturday afternoon against No. 13 BYU inside Allen Fieldhouse.

No doubt that Peterson, not AJ Dybantsa, should be the No. 1 pick in the 2026 NBA Draft.

No doubt that Kansas, at full strength, is a legitimate title contender.

Then halftime happened.

The Jayhawks survived, 90-82, and Peterson was amazing in the first half — 18 points on 6-of-7 shooting — but two minutes and 43 seconds into the second half, Peterson shot a 3 and missed and landed a little funny on his left foot.

Back on defense, Peterson immediately called for a sub and left the game at the next whistle, never to return. Kansas head coach Bill Self said after the game that Peterson had issues with cramps.

Bizarrely, the game at Colorado on Jan. 20 where he sprained his left ankle and Self missed because of a health scare, is the only game all season that Peterson has finished.

When Peterson is out there and his legs feel right and the Jayhawks are in sync with him, which they’ve started to look lately, Kansas looks like a real title contender. They led 53-33 at half against the Cougars, with Peterson outdueling Dybantsa, who scored 10 of his 17 points after halftime.

But every game, the Jayhawks (16-5, 6-2 Big 12) have to wonder just how much Peterson they’ll get that day.

Peterson is truly on another level when he gets rolling, and this day might have been his most electric performance yet. He had a steal and free throws that got him started. Then he hit a transition 3 and made a second steal, while guarding Dybantsa, and with his fellow freshman star on, he hit a step-back, mid-range fadeaway that set the tone that this was going to be his day.

His first half was reminiscent of the day in 2007 when Kevin Durant scored 25 first-half points at Allen Fieldhouse and KU legend Danny Manning said Durant was the baddest man who had ever played in the building.

Durant also left the game that day with an ankle injury, but he returned and finished with 32 points.

The Jayhawks have become accustomed to life without Peterson, and they managed to survive BYU’s surge in the second half. The Cougars (17-4, 5-3) have made a habit in big games of falling behind and furiously coming back behind Richie Saunders, who scored 24 of his game-high 33 points in the second half. They cut it to four with 1:27 left on two Rob Wright free throws, but KU answered with an 8-2 run.

KU was running on fumes at the end, with sixth man Elmarko Jackson also missing the second half. Self played a six-man rotation in the second half, but held on behind a season-high 21 points from freshman Bryson Tiller and with the help of Melvin Council Jr., who made a critical leaner when BYU had cut it to four.

Next up, Kansas is at Texas Tech on Monday, and everyone will wonder for two days if Peterson will play, and if so, how much?