MORGANTOWN, W.Va. -- Esa Ahmad awakened for a career-high 27 points and No. 18 West Virginia pulled away from No. 2 Kansas 85-69 on Tuesday night, ending the Jayhawks' 18-game winning streak.

"We knew it was a must-win. Losing just wasn't in our mind," said Ahmad, a sophomore forward whose concerted effort to attack the basket resulted in making 10-of-17 shots.

Kansas (18-2, 7-1 Big 12), which lost for the first time since its season opener against Indiana, led 59-58 with less than 10 minutes left before Ahmad's jumper put West Virginia ahead to stay.

The Jayhawks got 22 points from freshman Josh Jackson, who fouled out with 1:09 left amid an 11-0 run by the Mountaineers (16-4, 5-3).

"When they're turned up, which they were tonight, they're certainly one of the best teams in the country," said Kansas coach Bill Self. "We didn't play poorly for the first 30 (minutes), but obviously we closed miserably and they dominated us late."

After scoring only 10 points in his previous three games, Ahmad pledged to become more assertive, and his team benefited by beating the Jayhawks for the fourth consecutive year in Morgantown.

"I've been in a slump and I haven't been aggressive," Ahmad said. "These past few games I've just been passing the ball, sort of moving the ball. So, I tried to turn that around right out of the gate."

The Mountaineers, who lost their previous two games since knocking off then-No. 1 Baylor, got 11 points and five rebounds from Nathan Adrian, who triple-tipped a loose ball to take a rebound from the explosive Jackson. Guard Jevon Carter contributed nine points, eight rebounds and nine assists.

"Nate's got a lot of want-to, the way he chased the ball down," said West Virginia coach Bob Huggins. "Him and JC have been our heart and soul."

Devonte Graham added 17 for Kansas, and national player of the year candidate Frank Mason scored 15, albeit on 6-of-16 shooting with three turnovers. Self said his star point guard "wasn't really plugged in" as West Virginia ran double-teams his way and forced him to give up the ball.

"I didn't think he was nearly as good as he had been on either end," the coach said.

West Virginia guards Daxter Miles and Tarik Philip scored 10 each.

Kansas' 13 turnovers typically represent a solid day against Press Virginia, but the giveaways occurred at crucial situations. The Mountaineers finished with 19-7 edge in points off turnovers.

"We're about four possessions away from being undefeated," said Huggins. "I didn't want this to be a the-season-is-over game if we lost."

The Jayhawks missed 11 of their first 15 shots, with Mason starting 0 of 4 with two turnovers. Then he hit a 3-pointer and a transition layup, part of a 9-0 run that sent Kansas ahead 22-17. While Mason closed the half just 2 of 9 from the floor, Graham had 13 points, but Kansas trailed 38-35 at the break.

NOTES: West Virginia avoided its first three-game losing streak since February 2014. ... Mountaineers coach Bob Huggins' contract includes a $25,000 incentive for each regular-season win over the Jayhawks, money he donates to his late mother's cancer research fund. ... Kansas F Landon Lucas grabbed 10 rebounds but WVU won the rebounding edge 39-32. ... Kansas began a three-game stretch that includes No. 5 Kentucky and No. 6 Baylor. ... In a matchup of two of the worst foul-shooting teams in the country, West Virginia made 19 of 23 and Kansas sank only 6 of 15.