The Cougars (26-8) trailed by as many as 25 points in the first half and looked totally overmatched athletically for the first 15 minutes, but found a way to get back into the game just before halftime. They outscored the Gaels 38-17 in the second half to move into a matchup on Thursday against third-seeded Marquette in Louisville, Ky.
"It's part of that March Madness thing, I think," said BYU's Noah Hartsock.
Hartsock made a 3-pointer with around two minutes, 23 seconds remaining to give BYU its first lead, 71-70, Brock Zylstra added a big 3-point play and Brandon Davies and Matt Carlino made free throws in the final minute to seal the win.
Hartsock finished with 23 points and Davies added 18, while freshman Damarcus Harrison added 12 points off the bench.
"It was tough for us early," said BYU coach Dave Rose. "But our guys fought, and fought hard, and fought all game long and got a big win. I am really happy for our players."
The comeback was historic, but first, it was the worst start of the season for the Cougars, even surpassing that deep hole they found themselves in 10 days ago against Gonzaga. They trailed 49-24 with six minutes remaining in the first half when Iona's Ra'Shad James made a 3-point play, and nothing indicated the Cougars were about to mount a comeback.
Heads were drooping, shoulders were slumping, and Iona was making every shot look easy.
"Well, coming back from 25 points down is really satisfying, now that we won," Rose said. "Being down 25 points wasn't that satisfying."
Iona had a 55-40 lead at halftime, but was on a scoring drought that stretched into the second half. The Gaels went nearly nine minutes without scoring, and BYU capitalized.
"At the end of the day, we lost a game that we should have won," said Iona point guard Scott Machado, who had 10 assists, but just one in the second half. "It sucks. It sucks."
Iona shot 58 percent in the first half, cooling down after a torrid first 10 minutes, but just 24 percent in the second half as BYU's zone took its toll.
"I give BYU all the credit in the world for making the comeback. ... We missed countless layups and foul shots at critical times, wide-open shots," said Iona coach Tim Cluess.
Rose said when Zylstra made a 3-pointer with about 12 minutes left to cut the deficit to 10 and Iona took a timeout that he could see in his players' eyes they were on the verge of something special.
"We just started getting that momentum and confidence, and that's what helped us make those runs," Hartsock said. "… We just focused on chipping it down, doing that little by little."
And it resulted in a big win, one of the biggest and most memorable in BYU history.
In Short • BYU overcomes a 25-point first-half deficit and downs Iona 78-72 in an NCAA Tournament First Four game.
Key Moment • Noah Hartsock's 3-pointer with just over two minutes remaining gives BYU its first lead, 71-70.
Key Stat • Damarcus Harrison gives BYU 12 big points off the bench.
BYU's rally from a 25-point deficit for a 78-72 win over Iona on Monday marked the biggest comeback in an NCAA Tournament game, the organization said. Previously, the largest deficit overcome was 22 points in 2001 when Duke fought back to beat Maryland 95-84 in the national semifinals.