The Miami Hurricanes had championship T-shirts ready to unveil, and scissors on hand for cutting down the nets.
Georgia Tech put the celebration on hold.
Marcus Georges-Hunt followed his own miss with a tip-in at the buzzer Wednesday night, and the Yellow Jackets rallied past the Hurricanes 71-69 to prevent them from clinching the outright Atlantic Coast Conference title.
The Hurricanes (23-6, 14-3 ACC), who squandered a 13-point lead in the second half, lost their second straight game with a shot at an outright title.
"They deserve a celebration," Yellow Jackets coach Brian Gregory said. "I'm just glad it wasn't against us."
The defeat was the Hurricanes' third in four games after a 14-game winning streak, and they fell to 13-1 at home. They were already assured of a share of the title and can still clinch the championship outright by winning their regular-season finale at home Saturday against Clemson.
Georgia Tech (16-13, 6-11) beat a Top 25 team for the first time since March 2010.
"It's tough," Miami's Julian Gamble said. "You expect to win. But when you let a team get confidence and they start making shots, it's tougher and tougher to guard them down the stretch. You have to give them credit, because they hit some really tough shots."
The near-sellout crowd, subdued for much of the night, came alive late in the game. As the Hurricanes' lead dissipated, coach Jim Larranaga waved his arms and fist and screamed "Let's go," desperate for defensive stops.
But Miami's defense has gone soft during the recent slump.
"We've told the guys, all you have to do is let up a little bit, and guys start making shots against you," Larranaga said. "Our defense needs to be much better. When you take your foot off the pedal, it's hard to get it back."
Miami led 45-32 early in the second half. Gamble's three-point play with 12 minutes to go made it 56-45 before the Yellow Jackets rallied, taking the lead on Chris Bolden's fast-break layup following a steal with 3:38 remaining.
After a basket by Tech's Daniel Miller's made it 69-all with 2:14 left, each team misfired. Robert Carter Jr. intercepted a pass by Durand Scott to set up the final possession with 35 seconds left.
Georges-Hunt drove into the lane with 5 seconds to go and threw up a one-hander over Kenny Kadji that bounced off the rim. Georges-Hunt and Carter both appeared to get a hand on the rebound, and the tip-in was credited to Georges-Hunt for only his second basket of the game.
"He just put a shot up there, and then the ball just gets tipped around," Gamble said. "Honestly I don't even think one of their players tipped it in. I think it was one of our guys.
"It was kind of like being in disbelief, seeing the ball go in the basket and see the red light like that."
Bolden scored 21 points for Tech and went 4 for 8 from 3-point range. Miller added 17 points and five rebounds.
"I don't think many people thought we had a chance to win this game," Gregory said.
Tech stayed close by shooting 8 for 18 from 3-point range, including 6 for 10 in the second half. The narrow victory was a big turnaround for the Yellow Jackets, who had lost four league games by five points or less.
"We executed very well down the stretch," Bolden said. "We lost some games we could have won this season, but the lessons we've learned paid off tonight."
Kadji had 18 points and 11 rebounds for the Hurricanes. Scott had 17 points. But Miami went 5 minutes without a basket down the stretch and shot 36 percent in the second half.
The Hurricanes made six consecutive shots, capped by Kadji's 3-pointer, during a 14-0 run that put them ahead 25-14 midway through the first half. The margin was 43-32 at halftime.
"This loss definitely hurts," Gamble said. "Hopefully it hurts us enough to realize we have to get back to defending at our very best. I know we're going to fix the problem."