The Vallejo Admirals lost to the San Rafael Pacifics 5-3 on Tuesday at Albert Park to start a Pacific Association series.
San Rafael pitcher Angel Ventura went six innings, did not allow a hit and struck out 11 and walked two. Jose Casilla earned his 16th save.
The Admirals had just four hits overall, two by Chevy Clarke.
Frank Valentino took the loss as he went six innings, allowing six hits and three runs. He struck out six.
The Admirals dropped to 35-42 and the Pacifics improved to 50-27. Vallejo has already made the league playoffs but dropped out of a third-place tie with Pittsburg, which beat Martinez 5-4.