Pittsburgh, PA (SportsNetwork.com) - Steve Vasturia had a career-high 20 points, but none were bigger than his 3-pointer late in overtime.
Jerian Grant followed the sophomore's 3 with a difficult layup that secured the game, and bragging rights in the state of Indiana, for Notre Dame.
Grant posted 16 points, five assists and five rebounds and the third-seeded Fighting Irish took down Butler 67-64 to advance to the Sweet 16.
Butler sharpshooter Kellen Dunham tied the score at 55 with just under three minutes to play. It was 55-55 at the end of regulation.
Both teams had ample opportunities to go in front, but Notre Dame turned the ball over on three straight possessions and Butler shot 0-for-6 after Dunham's trey.
Things were heated in the Notre Dame huddle late in regulation after Zach Auguste committed what could have been a costly turnover. Auguste grabbed the rebound off Roosevelt Jones' missed jumper with five seconds left and turned up court, only to be called for a double dribble.
Irish guard Demetrius Jackson, who finished with 13 points and was open on the wing before Auguste was whistled for his violation, was visibly upset and had to be calmed down by his teammates. Pat Connaughton, Notre Dame's senior leader on and off the court, led the huddle, then made the game's biggest defensive play, blocking a Dunham jumper emphatically out of bounds.
Connaughton hit his first triple of the game two minutes into the extra session to break a 59-all tie. Then after Dunham made two free throws, the Irish took the clock down before Grant fired a pass to Vasturia in the corner. His 3 hit nothing but nylon.
Notre Dame held a three-point lead when Grant put the game out of reach, driving on Roosevelt Jones and sinking a lefty scoop layup with just under 20 seconds on the clock. Dunham missed two jumpers at the other end.
"They are obviously hard to play against and I Think we were able to do some things," said Butler coach Chris Holtmann. "We had the game where we wanted it. We just weren't able to make enough plays there late."
Notre Dame (31-5) will take on either Kansas or Wichita State in a Midwest Regional semifinal next week.
"What a magnificent college game," said Notre Dame coach Mike Brey, who found out earlier Saturday morning that his mother Betty Brey, 84, died of a heart attack. "It was a really special night. She was 84, a former Olympic swimmer, an unbelievable woman, a woman ahead of her time and probably the real driving force behind everything I've done."
"I think she was definitely with us down the stretch," Brey added.
Jones finished with 23 points for Butler (23-11). Andrew Chrabascz had 20 points and Kameron Woods pulled down 15 rebounds in the disappointing loss.
"(Jones) is definitely a physical player," said Grant. "He has an array of moves down there on the low block."
V.J. Beachem came off the bench and provided four quick points during an 8-0 Notre Dame run midway through the first half. Beachem's jumper at the tail end of the flurry made it 22-12, but Butler chipped away over the remainder of the half and got back in the game.
Jones' three-point play at 4:21 sparked a 9-1 run to tie the game at 27. It was 31-29 at halftime in favor of the Irish.
Connaughton's putback slam early in the second half put Notre Dame in front 37-31. Again, Butler battled back, but this time it didn't settle for a tie.
Jones and Chrabascz netted every point during an 11-0 Bulldogs run. Jones forced a timeout with his runner in the lane at 9:35, which gave Butler its largest lead at six. Eight straight at the other end led to the climactic finish.
Connaughton finished with seven points, nine rebounds and five blocks. Auguste posted seven points and 13 boards ... Jones played through a hyperextended left knee ... Butler outscored Notre Dame 32-24 in the paint.