The Grand Junction Rockies topped the Missoula Osprey, 8-7, for their fourth win in five games.
Missoula scored three runs in the eighth and ninth inning but came up short.
Grand Junction broke the game open with a four-run sixth inning capped off by a grand slam by Jeff Moberg.
Pedro Gonzales added a home run to the cause as well.
Lucas Gilbreath pitched 5.0 innings allowing three runs on seven hits.
Game two of the series will be tomorrow at Suplizio Field. First pitch is set for 6:40 p.m.