Illinois' stay atop the Big Ten standings was brief, and its return to the Top 25 could be as well.
The 22nd-ranked Illini return home Sunday afternoon to face Wisconsin, which is looking for a fourth straight win that would certainly come with a return to the AP Poll.
Illinois moved into first place in the Big Ten on Tuesday after Michigan beat Michigan State, but dropped down following a 54-52 loss at Penn State on Thursday.
The game was the Illini's first since a 79-74 upset of then-No. 5 Ohio State on Jan. 10, which moved them back into the Top 25 after they dropped out in late December.
Illinois (15-4, 4-2 Big Ten) looked rusty after the layoff, shooting 34.7 percent against the Nittany Lions. Jermaine Marshall blocked Sam Maniscalco's layup at the buzzer to seal the win after Tim Frazier put Penn State ahead seconds earlier.
"We didn't play well. I didn't coach well," coach Bruce Weber said. "I didn't prepare them well enough ... We weren't very sharp."
D.J. Richardson, who averages 12.6 points, was held to six on 2-of-11 shooting while Maniscalco, who missed three games with a sore ankle, missed all five shots in 27 scoreless minutes.
Richardson, who is battling a wrist injury, is averaging 6.5 points in four games this month. He hasn't been much better against Wisconsin, averaging 5.8 in five career starts, including a combined six points in two games last season.
Richardson's struggles have made it difficult for Illinois offensively. The Illini rank ninth in the conference in scoring, with 67.9 points per game, just above the Badgers' 65.5. But unlike Wisconsin, which averages only 9.0 turnovers, Illinois commits the most in the Big Ten with 14.2 per game.
With an offense prone to mistakes, the Illini are trying to get the ball inside more to 7-foot-1 center Meyers Leonard, who finished with 15 points on 12 field-goal attempts Thursday before fouling out late.
Leonard, however, knows it will be tough against Wisconsin's defense. The Badgers allow 49.0 points per game, fewest in Division I.
"They're very physical," Leonard said. "They use their lower body and don't do a lot of fouling with their hands."
After a tough start to conference play, Wisconsin (15-5, 4-3) has bounced back from a three-game losing streak with three straight wins. The Badgers defeated Northwestern 77-57 on Wednesday, shooting 12 of 23 from 3-point range.
Wisconsin had a two-point lead at the half, but held the Wildcats to 30.4 percent shooting after the break. Ryan Evans scored 17 points - 15 in the second half - and Jordan Taylor added 15.
The Badgers came in shooting 28.7 percent from 3-point range and 37.5 percent overall in conference play.
"It always helps when the ball's going in the basket," Taylor said. "I think we're just doing a better job like Mike (Bruesewitz) said, moving without the ball. We're passing up good shots for great shots."
Taylor came in shooting 39.4 percent, but connected on 5 of 9 shots against Northwestern. He's leading the team with 13.9 points and 4.4 assists per game, and averaged 20.5 points as the Badgers split two games against Illinois last season.