Gavin Sheets hit two of San Diego’s four home runs and drove in four runs, and Fernando Tatis Jr. robbed San Francisco’s Rafael Devers of a homer as the Padres beat the Giants 8-1.

These two weeks in which the Padres are playing only the Giants and Dodgers have provided some mood swings. The Padres moved into first place in the National League West with a sweep in San Francisco last week and fell back into second place when they were swept in Los Angeles over the weekend.

Taking the mound for the Giants will be right-hander Landen Roupp, who enters tonight’s game with a 3.45 ERA, 3.65 FIP, with 100 strikeouts to 43 walks in 104.1 innings pitched. His last start was in the Giants’ 7-6 loss to the Tampa Bay Rays on Friday, in which he allowed five runs on five hits with five strikeouts and a walk in three innings.