CHAMPAIGN —  After winning its first 12 games, the Illinois men’s basketball program was flying high.

The Fighting Illini found themselves ranked among the nation’s elite.

And then, it seemed like everything came crashing down with just three wins in the next 11 games.

But, Illinois first-year coach John Groce stayed with his system and the Illini are starting to reap the rewards with wins over No. 1 Indiana (74-72) and No. 18 Minnesota (57-53) last week.

“Our defense is getting better. We still have some errors that are being made, that we have to get corrected,’’ he said. “Our offense is improving. We are sharing the ball more.

“A lot of that has to do with trust at both ends of the floor, not only in the system, but in one another and their roles in what we are asking them to do.’’

Those victories have helped strengthen the NCAA Tournament possibilities for Illinois, but another big test awaits the Illini (17-8 overall, 4-7 in the Big Ten) tonight in the Assembly Hall.

The Purdue Boilermakers (12-12, 5-6) come into town and the last time these two teams met, it was Purdue outfighting Illinois 68-61 on Jan. 2 in West Lafayette, Ind.

“They beat us on a lot of toughness plays, especially at the end of the game,’’ Groce said. “D.J. Byrd made a really big difference from a physicality and a toughness standpoint. He made a lot of winning plays for them.’’

Byrd finished with 15 points, 12 of those coming in the final 10 minutes, and the senior grabbed an offensive rebound and took a charge in the final minute.

“Purdue has always played with a toughness,’’ Groce said. “We have to match that.’’

And in the past six games, he has seen plenty of good things for his team.

“There is no question that over the last six games, I’ve seen players, our offense, our defense has improved dramatically in a lot of areas and we have to continue to have that mindset,’’ Groce said. “Teams that focus on getting better everyday in February and March, when it starts to become a grind a little bit, are the teams that get better at the end of the year, and end up maxing out and reaching their potential.

“We want to be one of those teams.’’

Senior guard D.J. Richardson, the Big Ten Conference Player of the Week, has played a key role in the Illini improvement.

Richardson has scored in double figures in the last six games, beginning with his career-high 30 against Nebraska. In the wins over Indiana and Minnesota, the senior from Peoria had 36 points, four rebounds and five steals.

“Richardson, he’s playing at a really high level right now, not only offensively, but defensively,’’ Groce said. “He’s been an ‘X’ factor on both ends of the floor.’’

And another key performer for the Illinois defense has been 6-foot-11 sophomore center Nnanna Egwu.

“Nnanna had the highest grade out defensively of any player I’ve coached on Sunday,’’ said Groce.

And the Illini will need another big defensive performance from Egwu as A.J. Hammons, the 7-foot freshman center for the Boilermakers, is averaging 11.3 points and 6.8 rebounds a game.

“He is growing and getting better by leaps and bounds,’’ said Groce of Hammonds, who is averaging 19.3 points in Purdue’s last four games. “They do a good job of utilizing him and putting him in positions to score. He is tough to defend.’’

Tonight’s game is set for an 8 p.m. tipoff and the game can be seen on the Big Ten Network. Locally, the game can be heard on WDAN-AM 1490 and WDNL-FM 102.1.