Villanueva homered off Giants starter Andrew Suarez in the first. Jose Pirela added an RBI groundout in the fourth to drive in Hosmer.
Ross looked more like the pitcher who carried a no-hitter into the eighth inning against Arizona on April 20 than the one who got roughed up by Colorado in his most recent outing. The San Diego right-hander, who grew up across the bay in Oakland, allowed one run and had nine strikeouts in six innings.
Suarez gave up two runs and four hits over seven innings in his second career start. Suarez was recalled from the minors earlier in the day.
Padres: Catcher Austin Hedges was placed on the 10-day disabled list with right elbow tendinitis. Raffy Lopez was called up from Triple-A El Paso.
Giants: RHP Johnny Cueto was put on the DL because of inflammation in his pitching elbow. Cueto, who leads the major leagues with a 0.84 ERA, was on the DL in April with a sprained left ankle. … LHP Madison Bumgarner has been cleared to resume throwing and will begin on flat ground this weekend.
San Diego’s Clayton Richards (1-3, 5.35 ERA) pitches against San Francisco’s Derek Holland (0-3. 5.76) in a battle of lefties at AT&T Park on Wednesday afternoon. Richards has received no run support in three of his six starts this season.