Hayes' blast served as the game-winner, a two-run shot that sailed over the stands in right field in the fourth inning. It snapped a 1-1 tie and put the Beavers in the driver's seat for the remainder of the game.
Hayes' home run was sandwiched between Rodriguez's solo shot in the second and Smith's round-tripper in the fifth. The Beavers added two runs in the seventh on a groundout by Andy Peterson and single by Michael Conforto.
The three home runs by the Beavers marked a season-high for the club and boosted the team's total to 14, including seven in league play.
Rodriguez and Conforto each had two hits for Oregon State (37-8 overall, 17-4 Pac-12 Conference), which ran its win streak to eight games after taking its seventh consecutive game from the Golden Bears (21-26, 9-15).
Ben Wetzler made the start for the Beavers and gave up 11 hits but also struck out 10 California batters. He gave up two runs - one earned - and did not walk a batter to get the win and improve to 5-1 this season.
Wetzler's start qualified as a quality start - his fifth - and the 15th consecutive by OSU starters against Pac-12 opponents.
Dylan Nelson started for the Golden Bears and worked five innings before being relieved by Logan Scott to open the sixth. Nelson took the loss after allowing five hits and four runs with one strikeout. He is 1-5 on the year.
Cal scored solo runs in the third and seventh innings before Andrew Knapp doubled off the right field fence to trim OSU's lead to 6-4 with two down in the ninth. Scott Schultz, however, got Devon Rodriguez to ground out to Smith to end the game.
Oregon State makes the short trek to Keizer, Ore., to take on Portland in a non-conference game Wednesday at Volcanoes Stadium.
BASEBALL: Beavs sweep Cal
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