CHAMPAIGN, Ill. (AP) -- For one half Sunday, Purdue's shooting was brutal.
Airballs fell silently short. Balls that did find the rim clanked harmlessly off.
The shooting was so bad -- 28.6 percent -- that after one errant miss by JaJuan Johnson, Purdue coach Matt Painter eyed his leading scorer with exasperation as Johnson ran back upcourt, the coach's arms stretched wide and his hands raised as if to say, "What was that?"
But the No. 14 Boilermakers said their coach made just one calm request after the first half: Come out hard in the second.
They did, blasting the Illini with 54 second-half points, outrebounding them 28-9 over that stretch and locking up a comeback 81-70 win.
"That first half, we shot terrible -- I was missing layups," said Johnson, who finished with 24 points, sounding disgusted with himself over the memory. "When you make shots, it looks a lot better."
The Illini (16-9, 6-6 Big Ten) led or were tied for all but 1:17 of the first half and went to the locker room up 32-27. But they knew, coach Bruce Weber said, that a storm was coming.
"We told our guys, 'When you watch them, there's always one point in the game, they always turn it up,'" Weber said. "And they turned it up."
The result keeps the Boilermakers (20-5, 9-3) two games back and within reach of first-place Ohio State. The Illini, meanwhile, drop back to the middle of the Big Ten pack, and -- just three days after a big road win at Minnesota -- were left pointing fingers over who was to blame.
"A couple of us play hard and then three other people don't play hard -- it's not going to work," said Mike Davis, who finished with 16 points and seven rebounds.
The Boilermakers started their second-half push with a 10-4 run that gave them just their second lead of the afternoon. And they made it stick.
E'Twaun Moore, who finished with 20 points, hit a 3-pointer with 16:05 to play that put Purdue up 37-36.
Mike Davis made a pair of free throws with 12:48 left to cut Purdue's lead to 45-44. But Terone Johnson hit a 3-pointer 23 seconds later, and Ryne Smith followed that with a layup that made the score 50-44.
A minute later, with Illinois back to within 50-46, Smith and point guard Lewis Jackson combined for what might have been the offensive play of the game, and one that took the life out of the Illini crowd.
Jackson dribbled across the lane and spotted Smith open near the top of the key. Smith hit a 3-pointer for a 53-46 lead.
As much as JaJuan Johnson and Moore hurt Illinois in the second half, Weber said, role players like Smith made key shots that stung, while Jackson -- who finished with 10 points and five assists -- cut up Illinois' defense.
"It was all dribble penetration," Weber said when asked what the biggest offensive difference for Purdue was in the second half.
No matter how frustrated the coach looked on the sideline, Moore said Painter didn't lose his temper at halftime.
"He just said we've got to step it up," Moore said. "Just come out the first five minutes and try to pick up the tempo."
After Thursday's win raised Illinois' hopes for a strong finish and an NCAA tournament berth, the Illini said they let one slip away Sunday.
"We got out-toughed -- we didn't play as hard as we should've played and could've played," Davis said.
Weber declined to address Davis' complaints directly, but didn't entirely discount them.
"We've got a lot of guys who are offensive-minded players, and when they don't make a shot or don't do something, they don't maybe give quite the effort on the other end," he said.
Illinois was led by Brandon Paul's 23 points. D.J. Richardson finished with 13. Demetri McCamey returned to the starting lineup after playing off the bench against Minnesota, but finished with just 4 points, 10.8 below his average.
Purdue takes on No. 13 Wisconsin at home on Wednesday before hosting Ohio State next Sunday.
Painter said that, no matter how tempting, he and his team had to forget the Buckeyes for now.
"If you let guys float talk about a Big Ten championship," he said, "you're about to get beat."