Wilmer Flores slugged his fourth home run of the season, Heliot Ramos extended his extra-base hit streak and the visiting San Francisco Giants completed a three-game interleague sweep of the Houston Astros with a 6-3 victory on Wednesday.

Flores belted the first of three homers by the Giants and ignited an early ambush of Astros left-hander Framber Valdez (1-1). Flores’ 386-foot blast to left field drove home Willy Adames, who worked a one-out walk, and supplied the Giants a 2-0 lead in the top of the first inning.

Luis Matos recorded the second homer for the Giants to lead off the second, a 395-foot shot to center that was initially ruled a double before an umpire review credited Matos with his first home run of the year.

Valdez continued to labor and issued consecutive walks to Mike Yastrzemski and Tyler Fitzgerald at the bottom of the Giants’ order before Ramos struck.

Like Matos four batters earlier, Ramos bashed a two-seam fastball from Valdez to left-center for a double that plated Yastrzemski and Fitzgerald and extended the lead to 5-0.

Ramos has recorded an extra-base hit in six consecutive games, joining Felipe Alou in 1963 as the only players in franchise history to open a season with an extra-base hit in the first six contests.

Valdez, who tossed seven shutout innings against the New York Mets on Opening Day, settled down after Ramos’ double. He struck out Adames and Flores to cap the second and allowed just two additional baserunners while completing five innings. Valdez surrendered five runs on four hits and four walks with nine strikeouts.

The Astros chased Giants right-hander Landen Roupp when the first three batters reached safely in the bottom of the fifth. Roupp surrendered a run-scoring single to Zach Dezenzo with two outs in the second and kept the Astros at bay until he sandwiched walks to Chas McCormick and Isaac Paredes around a Jose Altuve single in the fifth.

Yordan Alvarez greeted Giants reliever Randy Rodriguez (1-0) with a two-run single that skipped by first baseman Casey Schmitt and into right field. But Rodriguez held the line there, notching strikeouts of Yainer Diaz and Jeremy Pena to preserve the lead.

Camilo Doval earned his second save of the season with a perfect ninth.