Thinned by injuries, the Huskies (3-3) went just seven players deep, but had enough to overcome the Billikens (3-3) and avenge a 13-point loss last season in St. Louis.
Wilcox had one of the most efficient games in Washington history, hitting 11 of 13 shots, including 4 of 5 on 3-pointers. He just missed his career high of 28 set in Saturday's home loss to Colorado State. The Huskies avoided their first three-game home non-conference losing streak since 1994.
Cody Ellis led the Billikens with 14 points off the bench. It was Saint Louis' last game away from home before conference play begins in early January.
Rob Loe added 13 points for Saint Louis, but leading scorer Dwayne Evans was held to eight points and stuck with foul trouble.
Washington needed a strong non-conference home win after losing on a last-second shot to Albany on Nov. 13 and getting routed by 18 against Colorado State last weekend. And after an ugly first-half with little energy - perhaps due to the rare 9 p.m. local time start - the Huskies woke up the final 20 minutes.
Abdul Gaddy added 16 points for Washington, which played its second straight game without starting swingman Scott Suggs, who has a foot injury.
With the game tied at 29-all at halftime, Washington started the second half on a 10-4 run led by the aggressiveness of Gaddy. The senior point guard gave Washington its first lead since 12-11 with a basket that made it 33-31.
Gaddy scored six straight points, aggressively going to the rim and calling for the ball.
Saint Louis stuck around thanks to its 3-point shooting. While the Huskies were working on the inside, the Billikens were hitting from deep. A trio of 3s capped by Loe's first of the game got Saint Louis within 47-46, but N'Diaye answered with consecutive baskets on the low block. N'Diaye then dived on the floor defensively to secure a loose ball, blocked a shot and altered another while Wilcox knocked down a 3 from the wing to give the Huskies a 54-48 lead with 7:19 left.
Wilcox continued his hot shooting with another 3-pointer out of a timeout to push the Washington lead to nine, and a shot clock violation by Saint Louis was followed with N'Diaye cutting for a dunk off a pass from Andrew Andrews to give the Huskies their first double-digit lead. The Billikens finally snapped Washington's 12-2 run when N'Diaye was late trying to block Jordair Jett's shot and was called for goaltending with 5:28 left.
Washington still led 63-53 before Mike McCall Jr. hit consecutive 3s while Gaddy and freshman Jernard Jarreau each missed the front end of one-and-one free throws. Loe then scored with 26.7 seconds left, and the Huskies' lead was down to 65-61. But Andrews hit one of two free throws, and the Huskies were able to dribble out the clock.
McCall and Jett both added 11 points for the Billikens.