Jerian Grant scored 16 points, including the clinching layup with 18 seconds left in overtime, and the third-seeded Irish edged the Bulldogs 67-64 in the NCAA Tournament on Saturday night.
Notre Dame (31-5) moved on to the Sweet 16 for the first time since 2003 and will play Kansas or Wichita State in the Midwest Regional semifinals on Thursday in Cleveland.
Steve Vasturia led Notre Dame with 20 points. Demetrius Jackson added 13 points while Zach Auguste had seven points and 13 rebounds for the Irish, who beat the Bulldogs for the first time in 26 years.
Roosevelt Jones played through an injured left knee while scoring 23 points for Butler (23-11), but another NCAA run ended abruptly in the extra session.
The Bulldogs had two chances to win it in regulation. Notre Dame's Pat Connaughton slammed Dunham's shot from the corner into the ground and senior center Kameron Woods couldn't convert an out of bounds alley-oop at the buzzer.
The Irish never trailed in overtime. Connaughton snapped a 59-all tie with a three-pointer from the right corner. The senior captain — who has delayed a lucrative baseball career for one last go-round at Notre Dame — then shook his head as he raced back down the floor and said “They're not gonna stop us.”
He was right. Kellen Dunham got the Bulldogs within a point with two free throws, but the Irish drilled their sixth — and last — three-pointer of the game when Vasturia knocked down a shot from the same spot as Connaughton.
Grant, a senior who missed most of the 2013-14 season due to an academic issue, then split the defense and laid it in with the shot clock ticking down as the Irish matched their deepest run under coach Mike Brey.
The two schools separated by 147 miles of Indiana highway met regularly from 1908-95, but had played just once in the last 20 years, a win by the Bulldogs in the preseason NIT in 2006.
The balance of power between the programs has shifted mightily in two decades. The Bulldogs are a March fixture with a pair of memorable national title game appearances since 2010 alone. The Irish have been modestly successful under Brey, but have struggled to translate regular-season wins into lengthy tournament runs.
The Irish promised this spring would be different. They shot their way to an improbable ACC Tournament title, beating Duke and North Carolina — a couple cities over from the heart of Tobacco Road — behind an efficient offense and an ability to limit mistakes.
It's a formula that has worked for Butler during its rise from mid-major marvel to newly minted citizen of the rejiggered Big East. The Bulldogs overcame the abrupt departure of coach Brandon Miller in October with gritty, grind-it-out defense and a relentless commitment to rebounding.
Notre Dame led by as much as 10 in the first half but the Bulldogs — as they tend to do this time of year — would not go away. Wearing reams of tape, compression pants and an unwieldy brace, Jones kept finding open space to get Butler back in the game.
A late three-pointer by Vasturia helped the Irish go up 31-29 at the break, though the half ended with a flashback of sorts. Jones stepped in front of a Notre Dame pass at half court and heaved one at the basket that clanged off the back of the rim. It wouldn't have counted — the red light came on before Jones let loose — but the moment vaguely resembled Gordon Hayward's last-second launch against Duke in the 2010 title game.
That shot missed too, and the Blue Devils cut down the nets. The Irish have four long rounds to reach that destination but moved closer after becoming the last of Indiana's four NCAA teams with a shot at playing in Indianapolis in two weeks.