AUSTIN, Texas — For the first 11 minutes and 27 seconds of the second half, Illinois went frigid.

Colorado erased a 37-21 halftime deficit in the second round of the NCAA tournament with a 21-0 run, a stretch that Illini head coach John Groce said he’s never been a part of anything of its likeness in his 20 years of coaching.

But if there’s one thing John Groce has mastered in his tenure, it’s surviving and advancing in March. Somehow, despite only making 3-of-22 shots in the second half, Illinois defeated Colorado 57-49 on Friday to advance to the round of 32.

“It was an odd game,” Groce said. “I don’t think I’ve ever been a part of something like that. It was a strange game in that regard.”

For how weird the game played out, Illinois’ bipolar shooting performance Friday was nothing new. Its signature win this season against Indiana was won by hot three-point shooting in the final five minutes of the game, and one of its most painful losses came at the hand of a nasty drought to start the second half on the road against Michigan State.

“I thought it was only fitting that the game was maybe about as strange a game that I’ve been associated with, that it would be that way with this group,” Groce said. ”We have done it the hard way a lot this year.”

Heading into the tournament, Groce wanted his team to focus on putting together two consistent halves of efficient basketball. That’ll have to wait until at least Sunday.

For seven-seeded Illinois to have a chance against two-seeded Miami, it’ll have to take the positive out of the first half of Friday’s game. Groce said the first half was one of the better all-around halves his team has played.

Illinois hit six 3-pointers and shared the ball efficiently while piecing together a stifling defensive performance that ended in eight Colorado turnovers before the break. An Illini team that averages just 10.2 assists per game (ranked 317th in the nation) dished out eight assists in the first half alone.

The Buffaloes suffered their own drought, when Illinois held them without a point for the final 7:06 of the first half and went on a 13-0 run over that stretch. Of course, that was only upstaged by Illinois’ offensive struggles in the second half, when it couldn’t make a 3-pointer to save its life and seemed to have no interest in driving toward the rim.

Finally, a Tracy Abrams layup ended the Illini’s nightmarish dearth with 8:33 remaining in the game. The bucket was greeted by a wave of cheers from the favorable Illinois crowd, which provided momentum as back-to-back 3’s by Brandon Paul and D.J. Richardson to give Illinois a 48-44 lead with 6:06 remaining.

“We’re mature players,” Richardson said. “We’re shooters. We’re going to keep shooting even if they don’t fall.”

Richardson scored 14 points,  Abrams recorded 13 and Paul added 17 and hit crucial free throws — he was 9-of-10 from the stripe — down the stretch to seal Illinois’ first NCAA Tournament win since March 18, 2011.

“This is a special opportunity,” Groce said. “We’ll be able to, I think, rev it up back up again on Sunday, no question about it. The next 48 hours is critical. We’ll do a lot of things to help get their minds and bodies back.”

For Illinois to continue surviving and advancing, it’ll have to fulfill Groce’s wishes for more consistent play and limit droughts to a minimum.

“This is March Madness,” Paul said. “That stuff happens all the time.”

Illinois will need to avoid these kinds of slumps, however, if it wants to keep its season going into next week. The Illini will face Miami (Fla.) on Sunday.

Ethan can be reached at [email protected] and @AsOfTheSky.