George Mason’s Bryon Allen, who hit a three-pointer with 21 seconds left to tie the game at 66, leaves the court with Patriots Coach Paul Hewitt. (John McDonnell/The Washington Post)

George Mason relinquished a 17-point lead in the second half Wednesday and lost to South Florida, 68-66, when Corey Allen Jr. made a fadeaway baseline jumper over a much taller defender with 2.4 seconds left.

Before that definitive shot, though, the Patriots unraveled in epic fashion.

They made one field goal over almost 11 minutes. They conceded a 23-1 run against a team that couldn’t make a jump shot. They were outscored 32-13 in the final 12 minutes. They missed three free throws in the last three-plus minutes, including attempts on consecutive three-point play opportunities that would have tied the score.

The turning point, though, came with about nine minutes left when George Mason’s Anali Okoloji fouled, and then stepped on, Anthony Collins. With a six-point play — four free throws and an alley-oop dunk — the Bulls turned a 12-point deficit into six.

The Patriots were never the same again.

“We were playing well, the game was going along well and that play happened,” Mason Coach Paul Hewitt said. “Something unusual happened and we didn’t respond very well to it.”

After the game, without the benefit of seeing a replay, Hewitt questioned the decision by the officials, who reviewed video before assessing the technical.

Okoloji’s “contention was that he was shoved in the back and lost his balance and his foot did make contact,” Hewitt said. “You have to officiate intent right there, especially if he got shoved. That is a huge play and you better be pretty sure about that because it changes the whole game.”

Patriots guard Bryon Allen concurred.

“It was a bad call,” he said. “The USF player pushed him right into the person. He didn’t purposely step on him. He wouldn’t do nothing like that, especially that crucial in the game. The momentum definitely carried over for them.”

Said Bulls Coach Stan Heath, who was standing directly in front of the incident: “He put his foot on him. I was really pleased our bench didn’t run out there. Our starters were smart enough not to retaliate. That was the play.”

After the six-point play, the Bulls (5-2) scored another seven points to take a 54-53 lead. The Patriots (5-3) did not lead again.

“The whole way the game swung shook us up a little bit,” Hewitt said.

Sherrod Wright (22 points) and Bryon Allen (14 points) missed late free throws after making layups and drawing fouls, leaving the Patriots behind by a point. Later, Bryon Allen hit a three-pointer with 21 seconds left to tie it at 66.

But after a timeout, the 6-foot-1 Corey Allen lofted the game-winner over 6-7 Jalen Jenkins. A desperation heave at the buzzer by the Patriots was off target.

Mason led 34-29 at halftime and embarked on a 14-4 surge after the break. Wright scored the first nine points, Corey Edwards banked a three-pointer and Marko Gujanicic scored in transition for a 48-33 advantage. The lead reached 53-36 with 12:17 left.

Equally impressive, the Patriots continued their outstanding defensive work. Interior resistance forced a turnover, and on the Bulls’ next opportunity, Wright provided weak-side help in leading to an airball.

A few minutes later, Erik Copes blocked Chris Perry’s layup attempt from behind, and in the process, knocked the ball out of bounds off Perry.

The prosperity abruptly ended, first with sloppy play and then the Okoloji incident.

“We didn’t come with the same energy,” Wright said. “We let them keep on punching us and we were taking it.”

The Patriots will face Oklahoma on Sunday in the BB&T Classic at Verizon Center.