CHICAGO (AP) Tommy La Stella and Brandon Belt each hit three-run homers, and the San Francisco Giants pounded the Chicago Cubs 15-4 on Saturday for their sixth straight win.

La Stella finished with three hits, including a double, five RBIs and scored three runs for surging San Francisco, which improved to a major-league best 92-50. The Giants entered 2 1/2 games ahead of the Dodgers in the NL West.

La Stella's home run - on the first pitch he saw from Tommy Nance in the fifth - thudded off Wrigley's right-field videoboard and capped a six-run rally that allowed San Francisco to pull away for its eighth win in nine.

Manager Gabe Kapler thought La Stella was a perfect pick as a leadoff man on Saturday, and it paid off. La Stella has missed three months this season with injuries, but is getting his timing back and grinding out at bats.

In this one, La Stella, a came up with runners on base and delivered.

''He's a perfect guy at the top of the lineup because he grinds pitchers,'' Kapler said. ''He can help set the table, but also drives the ball from time to time.

''He has some surprising pop. He's really good when he's upright like he was today.''

La Stella said he took no added pleasure in clobbering the Cubs, one of his former teams, but is happy to be getting back into form at the place.

''I just want to make sure I'm getting something in the zone,'' La Stella said. ''I think I was little more focused on that today.''

Belt went deep and doubled for the second straight day. The Giants 33-year-old first baseman has 23 homers, with 12 in his last 28 games, and 10 hits in his last 21 at-bats.

Evan Longoria had three RBIs on two hits and a sac fly, while Mike Yastrzemski drove in two runs. Kris Bryant had two singles, walked and scored two runs against his former team after going 0-for-3 with a walk in his emotional return to Wrigley on Friday.

The Cubs dropped their second straight, and third in four following a seven-game winning streak

Willson Contreras had two hits and two RBIs. Rookie Frank Schwindel had three hits.

Kevin Gausman (14-5) allowed three runs on eight hits, while walking none. The All-Star fanned nine and reached 200 strikeouts for a season for the first time in his career as he won his fifth straight decision.

''I knew I was getting close,'' Gausman said. ''Obviously a cool think to accomplish. something I've been trying to do for a long time.''

But Gausman kept his eye on the bigger picture.

''We believe were the best team in baseball right now and we're a dangerous team.''

Caleb Baragar tossed the final three innings for his second save.

Chicago's Zach Davies (6-11) was roughed up for the second straight start, allowing five runs on four hits and three walks in two innings

Cubs outfielder Jason Heyward left in fourth after sliding into third and getting kneed in the head by Giants shortstop Brandon Crawford. Crawford was covering the bag on a throw and struck Heyward as he tried to jump over him.

Following the game, bench coach Andy Green had no diagnosis on Heyward, but said the five-time Gold Glove winner would be watched closely over the next 24 hours.

''It was a tough collision,'' said Green who has been running the Cubs on the field since manager David Ross tested positive for COVID 19. ''Two strong guys running hard into each other.''

The Cubs jumped ahead 1-0 in the first, but the Giants stormed back with five in the second. La Stella's single with the bases loaded drove in the first two. Belt followed with his three-run shot.

Already leading 6-3, the Giants pulled away with their rally in the fifth, then tacked on two more in the eighth and one in the ninth.

ROSS TO RETURN

Ross is expected to rejoin the Cubs on Sunday. He's been away from the team since Sept. 3 after testing positive for the coronavirus.

Ross, who is vaccinated, remained asymptomatic and was closely engaged with the day-to-day operation of the Cubs until game time, according to Green, who filled in.

MORE LOVE FOR KB

Bryant got another standing ovation before is first at-bat on Saturday. The Cubs dealt the slugger to San Francisco at the July 30 trade deadline.

TRAINER'S ROOM

Giants: Wilmer Flores (left hamstring strain) remains on schedule to rejoin the team on Sunday. . RHP Alex Wood (positive COVID-19 test) will throw a bullpen session on Monday.... Both Bryant and Crawford were pulled late in the game with what Kapler called wrist issues.

Cubs: 2B Nick Madrigal, (right hamstring tear), acquired from the White Sox at the trade deadline for Craig Kimbrel, said he's been cleared to start running and expects to be at 100% in November. Madrigal was hurt running to first on June 9, then underwent surgery to repair the injury before the White Sox dealt him to the North Side. . RHP Keegan Thompson (right shoulder inflammation) threw a bullpen session on Friday and is expected to toss another in the next few days.

UP NEXT

Giants RHP Logan Webb (9-3, 2.64) faced Cubs LHP Justin Steele (3-2, 3.75) in the series finale on Sunday afternoon