In Williamsburg, W&M converted several foul shots in the closing minutes of the ECAC South game.
The Indians (18-7) completed a sweep of their nine league games. George Mason held a 66-65 lead after Carlos Yates made a jump shot with 4:53 remaining. Brant Weidner followed his own missed shot with a layup basket with 3:51 to go, and W&M led for good, 67-66.
William and Mary made 13 of 14 foul shots the rest of the way to hand George Mason its 10th defeat in 24 games. The Patriots are 3-5 in the ECAC South.
Keith Cieplicki led William and Mary with 26 points, including 10 of 11 free throws. Six of those foul shots came on one-and-one calls in the final minute. Overall, William and Mary made 27 of 36 from the line, to Mason's eight of 13. The losers were whistled for 32 fouls to the home team's 15.
Yates, in the top five of NCAA Division scorers entering the game with a 27.3 average, made eight of 22 shots from the field and ended with 21 points. Yates was often triple-teamed when he had the ball.
John Niehoff had 18 points for the Patriots, 14 helping the Patriots to a 39-36 lead at halftime.
William and Mary's record is its best in 30 years and the ECAC South championship its first basketball title of any kind. The game drew 7,450.