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 scored 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.