SAN FRANCISCO -- With seven rookies on their active roster, the Giants are in the midst of a youth movement, but it was their third-longest-tenured player who stole the show on Monday night.

Mike Yastrzemski launched two home runs, including a game-winning, three-run blast off left-hander Ray Kerr in the 10th inning, to lift the Giants to a 7-4 walk-off win over the Padres at Oracle Park and extend the club’s winning streak to eight games.

Yastrzemski homered off Padres right-hander Michael Wacha to bring the Giants within two in the sixth inning and then scored the game-tying run on Patrick Bailey’s sacrifice fly to cap a two-run rally in the bottom of the ninth and force extra innings.

The 32-year-old slugger delivered the final blow in the 10th. With the game tied, 4-4, Kerr intentionally walked Thairo Estrada to put a pair of runners on for Blake Sabol, who advanced the runners by laying down a perfect sacrifice bunt. That brought up Yastrzemski, who ended it by blasting a 3-1 fastball into McCovey Cove for his fourth career walk-off hit -- and his second walk-off splash hit. 

Yastrzemski immediately knew it was gone, dropping his bat and taking a second to admire the shot before beginning his memorable trip around the bases. With his 10th home run of the year, Yastrzemski secured his fifth career multi-homer game and his sixth splash hit. 

“That was probably the first time I’ve actually enjoyed it a little bit,” Yastrzemski said. “I’m always worried about the ball getting caught. I don’t really hit many where I definitely know.”

The Giants also got a solo shot from David Villar and five innings of one-run ball from rookie Keaton Winn, who gave up a homer to Juan Soto on the first pitch of his Oracle Park debut but then settled in to give San Francisco’s bats a chance to rally.

After matching the second-longest winning streak in the Majors this year, the Giants improved to 40-32 on the season, keeping them 3 1/2 games behind the first-place D-backs in the National League West.

“We’re just having fun,” Yastrzemski said. “We’re not taking anything too seriously. We’re always trying to stay competitive. We’re trying to take it one pitch at a time. When you try and score four runs at one time, that’s usually when it doesn’t work out very well, so we’re just trying to have good at-bats. I think everyone’s really bought into that, and it’s been working out well.”

The Giants outscored the Cardinals and Dodgers by a 52-19 margin during their perfect six-game road trip, but they were blanked through the first four innings and didn’t get on the board until Villar drove a first-pitch fastball from Wacha out to left-center field for a solo home run in the fifth.

Yastrzemski cut the deficit to 4-2 with another solo blast in the sixth before the Giants came back to tie the game in the bottom of the ninth.

Sabol opened the inning with a leadoff walk, advanced to third on Yastrzemski’s single to left field and scored on a wild pitch by Luis García to make it 4-3. J.D. Davis kept the line moving with another walk, putting runners on the corners with one out for Bailey, who lifted a game-tying sacrifice fly to left field to score Yastrzemski.

“That was probably more exhilarating,” said Yastrzemski, who had to hustle from third to beat Soto’s throw to the plate. “It was one of those plays where it could have ended up dropping in front. I just kind of hung out there for a second and made the right read, and luckily, I got in there just in time. I was pretty fired up that the game was tied up.”

Back-to-back walks by Villar and Casey Schmitt -- who entered Monday with only one walk over his first 133 Major League plate appearances -- loaded the bases with two outs, but Kerr struck out Joc Pederson to send the game to extras.

Closer Camilo Doval relieved Winn in the top of the 10th and struck out Manny Machado on the 11th pitch of the at-bat before retiring Xander Bogaerts and Jake Cronenworth to set up Yastrzemski’s heroics in the bottom half of the inning.

“Obviously, everybody is going to talk about Yaz, and for good reason,” manager Gabe Kapler said. “That was as clutch an at-bat as they get. He had several of them in the game. Obviously, he’s feeling really good at the plate right now. It doesn’t matter if there’s a lefty or a righty out there, you want him at the plate in the big moment.”