Frantz Massenat added 11 for the Dragons (15-5, 7-2 Colonial Athletic Association), who won their seventh straight.
Drexel trailed 15-14 with 7:11 left in the first half and went on a 13-2 run over the next 5:26. Lee's 3 put the Dragons up 27-17, and they led 30-21 at halftime.
The Dragons outrebounded William & Mary 34-26, leading to 14 second-chance points. Twenty seven of those rebounds came on the defensive end, as the Tribe shot just 35.8 percent from the field (19 of 53).
William & Mary struggled from long range, making just 4 of 22 (18.2 percent), including missing all but one of its 10 outside shots in the first half.
Marcus Thornton paced the Tribe (4-17, 2-7) with 18 points.