The Cardinals stormed back from a 10-point deficit, 63-53, at the 4:40 mark in the second half. Kris Gibbs-Smith, who chipped in 19 points on 7-of-11 field goal shooting, nine rebounds and four assists, ignited a 16-2 run in the closing minutes with a jumper. Williams, who made 10 of his 15 field goal attempts and 5-of-9 3-pointers, scored nine points during the decisive rally.
Ahmad Mims scored 20 points and Mat Burridge added a double-double with 17 points and game-high 10 rebounds for the second-seeded Lakers (20-7), who must await word Sunday night to learn if they will receive a Pool C bid to the NCAA Tournament.
Travis Gorham, who finished with 12 points, nine rebounds, four assists and three steals, made two free throws in the waning seconds to ice the game for the Cardinals, who are making their first SUNYAC championship game appearance since losing to Buffalo State in 1995.
Oswego shot 50 percent from the field in the first half to take a 35-30 lead. Plattsburgh was 13 of 30 for 43.3 percent.
But the Cardinals sizzled in the second half by making 14 of 22 field goals for a 63.6 clip, outscoring the Lakers 39-30 over the last 20 minutes.