Gaby Belardo hit the game-winning jumper with 11 seconds left as Canisius overcame an early 10-point deficit to edge Siena 62-61 Friday night.
Tomas Vazquez-Simmons blocked Ryan Rossiter's shot with 2 seconds to go to preserve the win.
Alshwan Hymes scored 19 points on 6 3s and Julius Coles had 18 for the Golden Griffins, who won their first Metro Atlantic Athletic Conference game of the season. They also snapped their 10-game losing streak to the Saints, who have lost only four of their last 44 league games.
Canisius (7-7, 1-3) fell behind 22-12, but trailed only 33-32 at halftime.
Belardo's layup with 3:12 to go pushed the Golden Griffins ahead 58-57 for their first lead since 2-0.
Coles hit a jumper, then Rossiter, who led Siena (5-9, 2-2) with 19 points and 14 rebounds, made two free throws.
A Rossiter jumper gave Siena a 61-60 lead with 19 seconds left.