Andrew McCutchen followed up Posey's hit with a three-run homer to right field, his fourth of the season, two batters after Joe Panik's RBI single tied the game. Posey added a solo shot in the eighth, his fourth.

Making his first MLB start, the 25-year-old Rodriguez (1-0) struck out six over six innings of one-run ball on five hits and two walks.

Jake Arrieta (5-3) knocked a home run and carried a shutout into the sixth on the mound before coughing up five runs for the Phillies, who lost 4-0 in Friday's series opener and 2-0 Saturday.

San Francisco has won four straight after losing six of seven. Philadelphia has dropped four of five and 10 of its last 16 games. The Phillies swept a four-game series against the Giants at home May 7-10.

Arrieta was on cruise control through five innings, lowering his season ERA under 2.00 before coming unglued in the sixth.

Mac Williamson struck out to lead off the inning, but singles from Gorkys Hernandez and Alen Hanson started the Giants' rally. Arrieta allowed eight hits and walked none while striking out four over six innings.

Arrieta helped himself with a solo shot in the third, a blast that traveled an estimated 375 feet to left. The home run snapped a 22-inning scoreless streak for Philadelphia.

It was Arrieta's sixth career homer. The former National League Cy Young Award winner hadn't gone deep since hitting a two-run shot last June 17 against Pittsburgh with the Chicago Cubs.

San Francisco hasn't named its starter for the opener of a three-game series with visiting Arizona on Monday. Philadelphia right-hander Zach Eflin (1-2, 4.50 ERA) will be on the mound for Tuesday's opener of a three-game set against the host Cubs.

--Field Level Media