Mike Yastrzemski capped a six-run explosion off Milwaukee closer Josh Hader with a walk-off grand slam in the bottom of the ninth inning Friday night, giving the San Francisco Giants a dramatic 8-5 victory over the visiting Brewers.

The homer was the third of the inning by the Giants off Hader (0-4), who took over at the start of the frame with a 5-2 lead. The left-hander gave up solo shots to Joey Bart, his sixth, leading off and Darin Ruf, his eighth, with one out.

With the Giants down 5-4, Austin Slater singled for his fourth hit of the night before he was caught leaning the wrong way by Hader on a pickoff attempt. However, Slater beat the throw to second for a steal, keeping the potential tying run on the bases with one out.

Pinch hitter Yermin Mercedes was hit by a pitch, and after Thairo Estrada's blooper fell into right field for a single, Yastrzemski jumped on Hader's first pitch for the game-winner. It was Yastrzemski's third career walk-off homer and his second slam.

The long ball was Yastrzemski's ninth of the year and it gave the Giants their fifth walk-off win of the season. The walk-off loss was Milwaukee's fourth of the season and second in three days.

Hader never previously allowed three homers in a game.

Sam Long (1-2), who pitched a scoreless top of the ninth, was credited with the win.

A five-run Brewers uprising in the fifth inning was difference for most of the night.

In the fifth, San Francisco first baseman LaMonte Wade Jr.'s fielding error with two on and two outs brought the Brewers within 2-1. Following a walk, Andrew McCutchen delivered a three-run double.

After replacing Giants starter Alex Wood, reliever Tyler Rogers served up McCutchen's hit, as well as a bases-loaded walk to Luis Urias that made it 5-2.

Wood was charged with three of the runs, all unearned. He gave up four hits in 4 2/3 innings, striking out seven and issuing no walks.

Brewers starter Brandon Woodruff lasted 5 2/3 innings, allowing two runs and five hits. He walked five and struck out four.

Yastrzemski finished with two hits for the Giants, who had been 1-for-9 with runners in scoring position before Estrada's single and Yastremski's homer to end the game.

Kolten Wong had two hits for the Brewers, who were out-hit 11-6.

--Field Level Media