Mike Yastrzemski bombed two home runs, right-hander Logan Webb pitched seven strong innings and the visiting San Francisco Giants completed a two-game interleague sweep of the rival Oakland Athletics with a 6-4 triumph Sunday afternoon.

Returning from a concussion, Thairo Estrada added a two-run homer for the Giants, who won the annual Bay Bridge Series from the A's 3-1.

Coupled with last year's 4-2 win, the Giants recorded back-to-back series victories in the Northern California showdown for the first time since the franchises started meeting annually in regular-season play in 1997.

Yastrzemski's homers, his 10th and 11th of the season, came leading off the third inning against A's starter Adrian Martinez (2-3) and with two outs in the eighth, a two-run shot off reliever Austin Pruitt that gave San Francisco a 6-2 advantage.

The multi-homer game was the fourth of Yastrzemski's career.

Martinez, who was called up from Triple-A Las Vegas before the game, was charged with two runs on four hits in 4 1/3 innings. He walked one and struck out five.

The Giants never trailed after Yastrzemski's first homer. They tacked on one run in the fifth on an RBI double by pinch-hitter Austin Slater, two in the sixth on Estrada's 10th homer of the season, and the last two -- which turned out to be the difference-makers -- on Yastrzemski's second blast in the eighth.

Webb (10-5) worked the first seven innings, leaving with a 4-2 lead. He allowed four hits and three walks while striking out five.

Seeking to build upon a nice run since the All-Star break, the A's rallied within 2-1 in the fifth on an RBI single by Skye Bolt. They cut it to 4-2 in the seventh on a run-scoring fielder's choice by Tony Kemp and again to 6-4 when Seth Brown smacked his 17th homer of the season, a two-run shot in the eighth.

Oakland then got the potential tying runs on base in the ninth on a walk by Kemp and a single by Sean Murphy, but Giants closer Camilo Doval struck out Brown and got Jed Lowrie to ground to short, locking up his 14th save.

Yastrzemski finished with three RBIs, while he and Crawford each had two hits and scored twice. Estrada added two RBIs for the Giants, who won consecutive games for just the second time since the All-Star break.

Brown had two hits and two RBIs for the A's, who have played winning ball (9-7) since the break. Murphy also finished with two hits, while Vimael Machin scored twice.

--Field Level Media