Sacramento opened a Pacific Coast League showdown series in Fresno Wednesday night by embarrassing the Grizzlies in an 18-4 blowout.
The win gives the first place River Cats a 4 1/2 game lead over the second place Grizzlies.
Josh Donaldson had three hits, including two home runs, on a five RBI night for Sacramento.
Adam Rosales also homered twice, including a grand slam in the ninth inning when Sacramento blew the game open with a ten run rally.
Rosales knocked in six runs on three hits.
The series continues with game two Thursday night at Chukchansi Park.