AMES, Iowa (Ticker) -- Freshman Curtis Stinson and Iowa State used a big second half to hand Kansas its first Big 12 Conference loss.
Stinson scored 16 of his 19 points after halftime and pulled down 11 rebounds as the Cyclones remained perfect at home with a 68-61 victory over the 12th-ranked Jayhawks.
Iowa State (13-4, 4-2 Big 12) erased a 29-21 halftime deficit behind Stinson, whose floater in the lane with 32 seconds left blunted a Kansas comeback and gave the Cyclones a 66-61 lead.
"Coach said we had to start attacking more, and we started taking it into the lane more," said Stinson, who missed 8-of-9 shots in the first half.
"Curtis Stinson is terrific," Iowa State coach Wayne Morgan said. "His basketball IQ is genius. He was made to play basketball."
After Keith Langford missed a long 3-pointer for the Jayhawks, Jake Sullivan made a pair of free throws with 11.5 seconds remaining to cap the scoring. Sullivan chipped in 17 points.
Jared Homan added 12 points and 11 rebounds and Jackson Vroman had 12 and eight for Iowa State, which snapped a 13-game losing streak against ranked opponents while improving to 12-0 at home.
"I think we had too much adrenaline going in the first half and nothing was falling," Morgan said. "At halftime, we got calmed down and played much better in the second half."
Langford led all scorers with 20 points and pulled down seven rebounds, but Kansas had a nine-game regular-season Big 12 winning streak snapped and fell into a first-place tie with Texas.
"That's about as poor as I've seen this team play," Langford said.
The Jayhawks were outscored in the paint, 28-12, and shot just 37 percent (23-of-62).
"It's one thing to guard plays, but it's quite another to guard players," Kansas coach Bill Self said. "Our big guys really struggled in the lane."
Iowa State missed 12 of its first 15 shots and the Jayhawks took their biggest lead, 27-16, on a 3-pointer by Michael Lee with 3:18 to go before halftime. They settled for an eight-point cushion at the break.
A dunk by Vroman sparked a 12-2 run and the Cyclones went ahead for good, 42-40, on a basket by Stinson with 12:39 remaining.
Will Blalock contributed 11 assists off the bench, becoming the first Iowa State player to reach double figures since current Indiana Pacers guard Jamaal Tinsley on February 28, 2001.