Gerardo Parra stung his former team with a three-run home run, and right-hander Joe Ross celebrated a happy homecoming with six shutout innings Wednesday afternoon, allowing the Washington Nationals to complete a three-game sweep of the host San Francisco Giants with a 4-1 victory.

Adam Eaton and Trea Turner combined for five hits and two runs for the Nationals, who finished off a 5-1 season-series win over the Giants.

Washington completed the pitching-dominated, three-game road sweep without using any of its top three starters -- Stephen Strasburg, Max Scherzer or Patrick Corbin.

Parra, who was released by the Giants in May after opening the season with a .198 average, hit his sixth homer in 57 games for the Nationals, a two-out shot in the third inning that also scored Eaton and Juan Soto.

The homer came off Giants starter Shaun Anderson (3-4), who was pulled after three innings, having allowed four runs and four hits. He walked three and struck out two.

Anderson is winless in his past seven starts.

The Nationals scored in the first inning after Turner and Eaton opened the game with singles. Turner eventually came home on Soto's groundout.

Pitching the entire game with a lead, Ross (2-3) coasted through his six innings, giving up just three hits. He walked two and struck out five.

The 26-year-old product of Berkeley, located due east from San Francisco across the bay, was pitching at Oracle Park for just the second time in his career. He was roughed up for four runs on six hits in just four innings on the previous occasion in 2015.

The Giants' best threat against Ross came in the fifth inning when they loaded the bases with two outs on singles by Kevin Pillar and Brandon Crawford and a walk to Austin Slater. But Ross got Mike Yastrzemski to pop out, preserving the 4-0 lead.

Tanner Rainey, Wander Suero and Daniel Hudson finished up, with the Giants' lone tally coming against Hudson in the ninth on a run-scoring double by Crawford.

Crawford had two hits, while Yastrzemski and Evan Longoria also doubled for the Giants, who have lost six of their past seven games.

The Nationals out-hit the Giants 9-6 in the game and 23-21 in the series.

--Field Level Media