Tri-City held Vermont hitless for a seven-inning span to get the victory at Centennial Field on Monday.
The Valleycats allowed a pair of hits in the first and then one more in the ninth to shut down the Lake Monsters and earn the 4-2 decision in the rubber match.
Tri-City’s pitching staff combined for 12 strikeouts in the contest, and Derek West got his first professional win on the mound.
Vermont fell to 15-22 this season, and the Valleycats improved to 14-21.
Lake Monsters travel to Hudson Valley to start a series against the Renegades at 7:05 p.m. and Tri-City will be on the road against Brooklyn at 7 p.m.