CHAMPAIGN, Ill. -- Bruce Weber thinks the Top 25 hasn't been kind to Illinois.
The Illini coach said that since the team edged into the rankings in mid-January, the first time in more than two seasons, it's forgotten to play the tough, smart defense that got it there.
"It was kind of human nature where we started thinking we were better than we are and we reinvented ourselves," Weber said. "We just had to get back to what we did and who we were by guarding and playing our butts off."
The memory lapse ended Sunday when the Illini (No. 21 ESPN/USA Today, No. 23 AP) knocked off Purdue (No. 13, No. 12), 66-48.
The Illini (19-5, 7-4 Big Ten) held the Boilermakers, who are playing without star forward Robbie Hummel, to season lows in scoring, shooting percentage (32.2 percent) and 3-point shooting (2-of-15).
"The key for us was our defense and our effort," Weber said. "We were able to get stops and get out in transition and get the crowd into it, and eventually broke their spirit."
Sophomore forward Mike Davis, who had 14 points and a career-high 16 rebounds, did much of the damage to Purdue (17-6, 6-4).
Davis has been as inconsistent as the rest of the team the past few weeks. Weber said Saturday that Davis had been fighting tonsillitis, as well as a related case of Bell's palsy, a temporary facial paralysis.
While that illness didn't directly affect Davis' play, Weber said, "Mentally it bugged him. I think it took a toll."
Davis benefited Saturday from the absence of Hummel, who has been out with a hairline fracture in his back. Hummel was cleared to play in the Boilermakers' loss to the Buckeyes on Tuesday, but still hasn't made it off the bench.
Purdue coach Matt Painter said Hummel, who hasn't practiced in weeks, still isn't ready.
"It just doesn't make sense to me [to play him]," Painter said. "His future's more important than the Illinois game."
Johnson scored 17 points to lead Purdue, while Jackson added 12.
"We were impatient," Painter said. "I liked our matchup with Johnson, but we have to do a better job of getting the ball inside to him."
The Illini pulled away late with a 23-6 run, a stretch of just over 10 minutes in which Purdue hit just one field goal.
But the Boilermakers, in spite of their offensive struggles, were never more than a couple of baskets and a defensive stop away from the Illini most of the afternoon.
Every brief Purdue run, though, was followed by a cold stretch and points from the Illini that revved their crowd up to earsplitting volumes.
Illinois opened the second half with a 9-4 run to go ahead 41-32, but Purdue rumbled right back with five straight points, including a crowd-calming dunk by Johnson, to pull to within 41-37.
Purdue went cold again midway through the second half, hitting just one field goal over a five-minute span. Illinois used that stretch to open a 12-point gap at 53-41 with just under eight minutes to play.
With their cold shooting, the Boilermakers were forced to look inside for openings that just weren't there. Beyond Johnson, Purdue's biggest inside threat, 6-foot-9 Namanja Calasan was just 1-of-7 on the afternoon.
Davis, on the other hand, thrived in the paint and outside.
The 6-9 Illinois sophomore had nine rebounds by halftime, and scored a half dozen of his points on soft jump shots.
"Mike Davis was the difference," Painter said. "He's got a good nose for the basketball. He's long and athletic."
Davis acknowledged that he'd been slowed by his illness, but said he's feeling better now than he has in a couple of weeks.
"I'm getting my wind back," he said. "I'm getting better and been hitting the weight room a little more and getting stronger and healthier."
Demetri McCamey added 13 points for Illinois, which never trailed.
Illinois' late run, the one that finished the Boilermakers, was keyed by six points from Davis and seven from Chester Frazier.
Frazier, an often-injured guard known for his defense and tough play, finished the game with 10 points.
Two of them, from under the basket and punctuated with a fist pump and a roar from the crowd, effectively finished the Boilermakers. The Illini went ahead 55-41 with 7:13 to play, and Purdue never again threatened.
Frazier's points were nice, but his defense mattered most. Weber credited him for holding E'Twaun Moore, who entered the game leading the Boilermakers with 14 points a game, to six.
"We just tried to make them make tough shots," Frazier said. "Stay in front of their players and keep them out of the paint."