Livingston has the clinching free throws with under a second left but it was Goanar Mar, who had 16 points, who made it 78-75 with two foul shots at 4.1 seconds. Then Luwane Pipkins, who had his fifth 30-point game of the season for the Minutemen, was called for a push-off offensive foul as he was driving upcourt for a potential game-tying shot, with 1.4 to go.
George Mason (16-16), which plays fourth-seeded Saint Joseph's in the quarterfinals on Friday, did not make a field goal in the final four minutes, missing its only two attempts while going 9 of 10 from the foul line.
UMass (13-20) missed six straight shots after a 3 by Pipkins but the Minutemen ahead 67-64 with 5:46 to play until xx Hines had a tip-in at 6.2 that cut George Mason's lead to 76-75.
Pipkins, who scored 31, had five 3s to set the school record with his 107th this season and also joined the 1,000-point club.
UMass shot 53 percent but George Mason turned 20 offensive rebounds into 26 second-chance points.
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