Curt Casali put a happy ending on his nightmarish game when he doubled home Steven Duggar from first base with one out in the last of the 10th inning, capping a two-run rally that gave the host San Francisco Giants a 6-5 victory over the Oakland Athletics on Saturday night.

Down 5-4 after a Matt Chapman sacrifice fly in the top of the inning, the Giants got even on an RBI single by Duggar off Athletics reliever Burch Smith (1-1) that scored Brandon Crawford with one out.

Casali, who had struck out in each of his previous four plate appearances, then lined a double into the left-field corner, enabling Duggar to race home with the Giants' first walk-off win of the season after seven straight defeats.

San Francisco closer Jake McGee (3-2) was credited with the win despite allowing a run without issuing a hit in the top of the inning. The Giants (50-26) are the first team in the majors to reach 50 victories.

The A's had gone ahead 5-4 when Seth Brown, who began the inning at second base, advanced to third on an infield out by Ramon Laureano and then scored on Chapman's third RBI of the game.

The Giants, who extended their winning streak to five in a row, nearly ended the game in regulation when, with two on and two out in the last of the ninth, Crawford singled to left field.

But A's left fielder Tony Kemp fielded the hit on one hop and fired to third baseman Chapman, whose relay throw to the plate was in plenty of time to nail LaMonte Wade Jr.

The see-saw affair saw the A's blow three leads and the Giants one, with home runs playing key roles in each comeback.

After the A's had opened the scoring in the third on an Alex Wood wild pitch, the Giants went up 2-1 in the fifth against Oakland starter Frankie Montas on a two-run homer by Wade, his fifth of the season.

The A's tied the game on a Mitch Moreland pinch-hit RBI single in the sixth, then went up 4-2 in the seventh when Chapman belted reliever Zack Littell's second pitch for a two-run homer, his 10th of the year.

But back came the Giants, getting within 4-3 on a Wilmer Flores RBI single in the last of the seventh, before drawing even in the eighth on a solo homer by Donovan Solano, his third of the season, off Jake Diekman.

Both starters pitched well, but neither got a decision.

Montas was pulled after five innings, having allowed two runs on two hits. He walked three and struck out five.

Wood also allowed two runs, one earned, on four hits in 5 1/3 innings. He walked one and struck out eight.

Wade and Solano had two hits apiece for the Giants, who captured the series opener 2-0 on Friday night.

The loss was just Oakland's second in eight walk-off games this season. They fell to 2-2 in extra-inning affairs.

--Field Level Media