Musgrove (5-0) held the Giants scoreless over seven innings, allowing four hits and three walks. The Padres (26-14) have won each of his first eight starts, the second-longest streak in club history. San Diego won Andy Hawkins’ first 12 starts in 1985.
Machado, who entered Saturday leading MLB in OPS (1.005), followed up his three-hit night Friday with a towering homer to open the scoring Saturday. Machado hit a 98 mph fastball by Carlos Rodón (4-3) 425 feet to center for his eighth homer of the year, and first since May 5.
The Padres added to the lead when Luke Voit led off the sixth with a double, moved to third on a single by Austin Nola and scored on a safety squeeze by Trent Grisham.
The Giants (22-17) got doubles by Mike Yastrzemski, Joc Pederson and Tommy La Stella against Musgrove but couldn’t get a runner to third base. Wilmer Flores homered in the eighth against reliever Robert Suarez.
Taylor Rogers recorded his MLB-best 16th save, working around a leadoff single by pinch-hitter Austin Slater.
Musgrove hasn’t allowed more than two earned runs and has pitched at least six innings in all of his starts. The only other pitcher to start at least seven games and have his team win each one this season is Luis Severino of the Yankees.
Jurickson Profar, who had two baseballs and one beer bottle thrown at him from the stands when he played in left field in the Padres’ 10-inning win Friday night, was the designated hitter on Saturday. He reached base in all five of his plate appearances, with two singles, two walks and an error by first baseman Darin Ruf.