CHICAGO (AP) -- The Illinois-Chicago Flames have been to three NCAA tournaments in the last nine years, but they've never scored a bigger regular-season win than they did Wednesday night.

Butler's Brandon Crone, right, goes up for a shot as Illinois-Chicago's Jovan Stefanov (4), of Serbia, defends during the first half of a college basketball game in Chicago on Wednesday, Jan. 10, 2007. Illinois-Chicago won 73-67 in overtime. (AP Photo/Brian Kersey)

Josh Mayo scored 19 points and hit a big 3-pointer in overtime to lead the Flames to a wild 73-67 victory over No. 12 Butler at the UIC Pavilion. The Flames had never defeated a team ranked that high.

Butler's A.J. Graves scored a season-high 31 points, 26 in the second half and 3 in overtime, but it wasn't enough to hold off the Flames, who led for nearly the entire game.

"Our defense wasn't good tonight," said a dejected Graves, who sat in the stands after the game. "No matter how well we play offensively, we have to play better defense. That's what we pride ourselves on and we haven't nothing to be proud of tonight."

UIC guard T.J. Gray scored 13 points and hit four straight free throws to ice the victory for the Flames (8-9, 3-1 Horizon League), who beat a ranked team for just the second time in school history.

"They deserve to have something good like this happen to them," said interim Flames head coach Mark Coomes.

Since the end of December, the Flames have lost three players and their coach, Jimmy Collins, who is out indefinitely after taking a leave of absence in late December. Collins had surgery this month for abdominal surgery to repair an aortic aneurysm.

"Our guys are maturing," Coomes said. "They're keeping things in perspective."

Butler, which hasn't been ranked this high since the 1948-49 season and won the preseason NIT this year, came back to force overtime behind Graves' second-half shooting. After going 0-for-7 from 3-point range in the first 20 minutes, Graves hit 6 of 10 second-half 3-pointers. The guard hit a deep 3 to cut the deficit to 58-56 with 20 seconds to go, then drew a foul and hit both free throws with 16.3 seconds left to tie it. He missed a desperation shot at the buzzer.

The Bulldogs (14-2, 3-1) led twice early in overtime but UIC went 3-for-3 on 3-pointers and 6-for-6 from the free throw line in the extra period.

Forward Jovan Stefanov's second 3 in OT made it 66-64. Butler retook the lead when Graves matched it. But Mayo responded with a 3-pointer for the Flames and Gray finished Butler off from the line.

"I wasn't worried about it," Gray said of overtime. "It's just another 5 minutes. It was zero-zero. We just had to come out and get it done."

Graves had just 2 points in the first half on 1-for-10 shooting. He made up for it in the second, scoring 19 points in an eight-minute stretch. He hit 5 of 6 3-pointers in that span, all in front of Butler's bench.

"I felt confident all game," he said. "They just weren't falling in the first half."

UIC center Scott VandeerMeer had 11 points -- 10 in the first half -- and added 10 rebounds and six blocks. Stefanov added 11 points and Othyus Jeffers had 9 points and 12 rebounds.

At 6-11, VandeerMeer had four inches on the tallest Bulldog. He also said he played with some extra weight on his shoulder.

"I watched them on TV and I understood why they were 12, but it made me mad," he said. "I thought we have a good team, we should be where they are. I went in with a chip on my shoulder because I think we're just as good."

Brandon Crone had 14 points for Butler.

UIC led 22-15 at the half, thanks to poor shooting by Butler. The Bulldogs shot 17.9 percent in the half, hitting just 5 of 28 shots -- 2 of 17 3-pointers -- and 3 of 7 free throws.

The Flames didn't shoot well, just 38.2 percent for the game, but they hit 11 3s and made 20 of 26 free throws, all in the second half.

"UIC played great tonight," Graves said. "My hat's off to them."