BUFFALO, N.Y. (AP) Rookie Thomas Vanek scored his second goal of the game 34 seconds into overtime to give the Buffalo Sabres a 3-2 preseason victory over Washington Capitals on Saturday night.

Ales Kotalik also scored in Buffalo's preseason opener, and goalie Martin Biron stopped 27 shots.

Matt Pettinger and Bryan Muir scored for Washington, which squandered two one-goal leads. The Capitals opened exhibition play Friday night with a 6-0 loss at Carolina.

Vanek, the fifth player selected in the 2003 draft out of the University of Minnesota, converted Daniel Briere's pass through the slot in overtime. Driving to the right of the net, Vanek managed to get his stick on the puck despite being checked by Muir - his weak shot dribbling in just behind goalie Maxime Daigneault.

Vanek forced overtime when, set up by Briere, he blasted a 45-footer past Daigneault midway through the third period.

Capitals goalie Olaf Kolzig stopped all 22 shots he faced through two periods before being replaced by Daigneault.

Buffalo did have one goal disallowed when Andrew Peters was penalized for goalie interference after driving into the crease to tip in Teppo Numminen's shot from a bad angle in the first period.

Vanek capped his night when he scored Buffalo's lone goal in the shootout session, which the NHL is introducing the season to eliminate tie games. All preseason games, no matter what the score, feature a shootout.