Point guard Bryant McIntosh's driving layup with 27 seconds left lifted Northwestern to an 81-79 overtime victory over Virginia Tech on Tuesday night in Big Ten/ACC Challenge action at Cassell Coliseum.

Virginia Tech used its final timeout to set up a clearout for junior guard Seth Allen, who led all scorers with 25 points, but Northwestern double-teamed him at the top of the key to force a loose ball and a mad scramble. Hokies freshman swingman Chris Clarke tried a 15-foot baseline fadeaway at the buzzer, but it rimmed off to give the Wildcats the win.

McIntosh posted 19 points and senior guard Tre Demps added 17 for the Wildcats (6-1), who are off to their best start since 2012.

Sophomore guard Justin Bibbs contributed 17 points for Virginia Tech (4-3). Junior forward Zach LeDay, the Hokies' leading scorer with 19.0 points per game, netted his only points when he hit a pair of free throws with 5:35 left in regulation.

Both teams had chances to win in regulation. Clarke backed down his defender with 26 seconds left in search of Virginia Tech's first lead since 3-2, but he missed a post move with a high degree of difficulty and the Hokies lost a battle to save the ball from going out of bounds.

The Wildcats cleared the floor for Demps to go one-on-one, but his floater in the lane with 0:04 left didn't fall. Allen seized the rebound and unleashed a runner from 70 feet that banged off the rim at the buzzer.

The Hokies scored the first 4 points in overtime before Northwestern's Sanjay Lumpkin and McIntosh canned back-to-back 3-pointers to trigger another taut finish.

Northwestern backup center Joey van Zegeren, a graduate transfer who spent the last four years at Virginia Tech, gave the Wildcats a huge lift late in regulation against his former team with a pair of ferocious two-handed slams. Van Zegeran averaged 5.7 points, 4.3 rebounds and 1.2 blocks in 76 games before being suspended indefinitely on Jan. 2, 2015.