CHAMPAIGN, Ill. (AP) For 20 minutes Wednesday, Illinois kept Notre Dame point guard Demetrius Jackson in check.
Steve Vasturia was scoring for the Fighting Irish, but with Jackson frustrated and quiet with just four points, the Illini had the edge and a halftime lead.
Then Jackson woke up.
He finished with 21 points and Vasturia did, too, leading Notre Dame to a comeback 84-79 win over the Illini in the ACC-Big Ten Challenge.
''I got some good looks,'' Jackson said, crediting teammates with creating space for him to shoot in the second half. ''It's just up to me to step up and knock those down.''
Notre Dame coach Mike Brey said the team's switch to a zone defense in the second half made a big difference.
''We were having such a hard time in man-to-man, you've got to try something else,'' Brey said. ''My feeling was, we're going to ride this till the end because I think it's the only option we've got.''
That change in defense shut the Illini down. Illinois (3-5) shot 50 percent in the first half but was 13 of 37 in the second 20 minutes. That included an ice-cold 2 of 18 start.
''I didn't like our start to the second half,'' Illinois coach John Groce said. ''I had a veteran group out there. I did not think we were ready to play at all.''
The Fighting Irish spoiled the reopening of Illinois' recently renovated State Farm Center with the win.
Notre Dame (5-2) had lost two of three coming into the game and had fallen out of the Associated Press Top 25.
But a 3-pointer from Vasturia with 1:54 to play put Notre Dame up 72-62.
Illinois rode tough defense and the energy of the first night back in its campus arena to a 41-33 halftime lead.
Malcolm Hill led Illinois with 19 points, while Kendrick Nunn had 13 points and seven rebounds.
Zach Auguste added 16 points with 14 rebounds for Notre Dame.
Illinois came into the game facing the challenge of controlling Jackson and, missing starting center Mike Thorne, 6-foot-10, 245-pound Auguste.
Through the first 20 minutes, Illinois blunted the offense of both. Jackson went to the locker room with a quiet four points and one assist and Auguste had seven points and four rebounds.
But in the second half Jackson started finding his stride.
The senior hit a 3-pointer from the left, just in front of the Notre Dame bench, with 9:51 left in the game. The Irish were up 58-49 and Jackson flashed a big grin at the bench as he spun to head back up court.
Hill said the difference between Illinois' two halves was frustrating.
''We need to put the two pieces together,'' he said. ''Our second half start was bad. We started off good in the first half.''
Notre Dame: The Fighting Irish had a flurry of turnovers early, including four in the game's opening minutes. But they finished with nine. Jackson was 3 of 4 from 3-point range and Vasturia 3 of 5.
Illinois: Illinois used a combination of Maverick Morgan, Michael Finke and Leron Black to fill in for Thorne, who suffered a torn meniscus last weekend against Iowa State. The three subs combined for 21 points and nine rebounds. Illinois turned the ball over just three times.
Brey called the win important for a team he said is trying to find an identity, and particularly after the Fighting Irish lost two of their last three. On the road in front of a big, loud crowd Wednesday, Notre Dame never gave the impression it might buckle, Brey said. ''Even down eight, down 10, we were really calm,'' he said.
The renovated State Farm Center changed the look of the interior, making most of the 15,544 seats dark blue and adding premium seats, box seats, new concessions and other features. The $169.5 million project, which isn't quite finished, reduced the capacity by about 1,000. But the project boosted the number of seats for the Orange Krush student section from 700 to 1,200 and wrapped it around three sides of the court. Illinois also named the new court after Illini coaching legend Lou Henson, who was at Wednesday's game. Henson is Illinois' winningest coach, with 423 wins over 21 seasons.
Notre Dame hosts Stony Brook on Tuesday.
Illinois hosts Western Carolina on Saturday.