Purdue coach Matt Painter warned his team about the final play that led to the Boilermakers' 67-65 loss to Butler in the Crossroads Classic on Saturday in Indianapolis' Conseco Fieldhouse.
With a second remaining, Butler's Andrew Smith tipped a missed jumper from Roosevelt Jones to seal a comeback from a deficit that reached as high as 12 points in the second half.
"Normally what happens is the second play beats you, and that's what beat us," Painter said. "We changed a little bit in how we were going to defend. We said, 'You have to make sure you switch on to somebody. And when you do switch on to somebody, you've got to block out the guy you switch on to.'
"Exactly, what we told them they needed to do, they obviously didn't. You got to give credit to the Butler player for making the play."
Purdue forward Robbie Hummel said he was at fault for not rotating over and blocking out Smith on the Bulldogs' game-winning basket.
"That play is my fault," said Hummel, who scored 16 Saturday. "I'm supposed to switch to the ball screen, and I didn't. Because of that, Andrew Smith was able to get that tip in."
The Boilermakers sprinted out to an 11-2 lead in the opening 4 ½ minutes and took a 46-35 lead into halftime after shooting 55.6 percent.
But Purdue's offense all but stopped in the second half.
The Boilermakers were held to 20.7 percent shooting in the second, and they couldn't get anything to fall in the final minutes after Hummel sank one of two free throws a 64-56 lead with 6:40 to play.
Purdue didn't score another point until guard Lewis Jackson made the second of two free throws to tie the game at 65 with 10 seconds to play. In the 6:30 span, Purdue missed nine shots from the field, including two layups. Jackson also only made one of three free throws in the final 28 seconds.
Hummel, who scored 12 in the first half, didn't get his first points of the second until sinking a three-pointer with 9:24 to play. Ryne Smith was held without a second-half point after leading Purdue with 14 in the opening half.
"I thought we really defended well in the second half and really defended poorly in the first," Butler coach Brad Stevens said. "But we took our chances and tried to guard Hummel and Smith as hard as we could. I didn't think it was hard enough in the first, but we are lucky to win."
The loss to Butler was the second time in the last four games that Purdue let a big halftime lead slip away.
The Boilermakers, who led the Bulldogs 46-35 at halftime, also had an 11-point lead over No. 8 Xavier on Dec. 3. But Purdue lost that game 66-63.
"We just have to get back to work," Hummel said. "We have to figure it out as a team. It is disappointing right, and it hurts. But if we can learn from it, like we said after Xavier, that could be a positive."