Mac Williamson homered and drove in four runs in his 2019 debut and the visiting San Francisco Giants routed the Colorado Rockies 14-4 on Tuesday night.
Williamson, who hit three home runs Monday night for Triple-A Sacramento, was called up Tuesday and paid immediate dividends when his three-run homer off Antonio Senzatela broke a 1-1 tie in the fourth.
Evan Longoria and Kevin Pillar also homered for San Francisco, Joe Panik had three hits and Brandon Belt had two doubles.
San Francisco starter Madison Bumgarner (2-4) gave up three runs on eight hits over six innings. He struck out eight and walked one.
Senzatela (2-2) gave up seven runs on eight hits — three of them home runs — in 4 2/3 innings. He entered the game 5-0 with a 3.35 ERA in his career against the Giants.
Charlie Blackmon and Chris Iannetta homered for the Rockies and Raimel Tapia had three hits.
Blackmon led off the bottom of the first with his fifth home run of the season. It was his second leadoff homer of the season and the 32nd of his career.
Longoria tied it in the second when he connected with a 3-2 fastball for his fifth home run.
The Giants scored five runs off Senzatela after the first two batters made outs in the fourth.
Belt doubled, Longoria walked on four pitches and Williamson homered on a 1-1 slider. After Brandon Crawford singled, Pillar hit his sixth home run of the season to make it 6-1.
Colorado got a run back in the bottom of the fourth when Ian Desmond’s triple scored Nolan Arenado, but the Giants answered in the fifth as Williamson’s two-out single scored Belt, who had doubled with two outs.
Iannetta’s homer in the fifth pulled the Rockies within 7-3 before the Steven Duggar’s two-run single in the eighth made it 9-3 and the Giants added five runs in the ninth.