Temple's Quenton DeCosey made a pair of free throws in overtime then watched as UConn's Daniel Hamilton missed three that could have won the game for the Huskies.
The Owls held the defending national champions to a single field goal in extra time and held on for a 57-53 win in the American Athletic Conference opener for both teams.
Jesse Morgan scored 17 points and DeCosey finished with 11 points for the Owls (10-4) who have now won four straight and six of their last seven, a string that included a 77-52 upset over Kansas on Dec. 22.
"This was just a fight the whole way," said Morgan, who was 4 of 10 from 3-point range. "We stuck together and we pulled it out."
Amida Brimah had 12 points to lead UConn (6-5) while Hamilton added 10 points and 12 rebounds.
Temple led 55-53 after DeCosey's free throws with 2:48 left in overtime. The score was the same when Hamilton was fouled by DeCosey on a 3-point shot from the top of the key with less than 3 seconds remaining. Hamilton missed the first two and was called for a lane violation after intentionally missing the third.
"I didn't think I fouled him," DeCosey said. "But the ball don't lie. We got some free throws too, and we were able to pull it out."
Will Cummings made two foul shots on the other end to seal the win. The teams were a combined 2 of 11 from the floor in overtime.
UConn's star guard Ryan Boatright left the game after suffering a deep bruise to his left thigh late in the first half. He tried to start the second, but hobbled off the court after the first Temple possession.
"We needed someone to keep the game composed and control the game," said Brimah. "Ryan could have done that for us."
The Owls came in ranked third in the American Athletic Conference schools in scoring defense, giving up just 61.5 points a game. They held UConn to 39 percent shooting, but hit just 31.6 percent of their own shots.
"It's sort of like getting blood from a stone at this point," said Temple coach Fran Dunphy. "Both teams know each other pretty well."
Temple led for almost 35 minutes, but never by more than six points in the second half.
A pair of free throws from Hamilton cut the deficit to 51-49 with 47 seconds left in the game, and the Huskies tied it on a breakaway dunk by Rodney Purvis with 12 seconds left after Daniel Dingle missed an open 3-pointer.
Dingle also missed a layup just before the buzzer that would have given the Owls the win in regulation.
Temple led 25-21 at halftime, despite shooting just 27 percent from the floor.
"They weren't going to back down and they kept coming at us," said DeCosey. "The tougher team, whoever wanted it more, was going to win. That was us tonight."
Temple has already surpassed its win total from last season, when the Owls went 9-22.