PHILADELPHIA -- Maikel Franco, who tied the game with an eighth-inning, two-run single, singled home the winning run in the 12th as the Philadelphia Phillies rallied for a 5-4 victory over the San Francisco Giants on Wednesday night.

Ryan Howard and Cameron Rupp hit back-to-back homers in the seventh inning for the Phillies, who erased a 4-0 deficit to win for the fourth time in six games.

Buster Posey drove in three runs for the Giants, who are a major-league-worst 4-13 since the All-Star break.

George Kontos (2-2) hit Tommy Joseph with a pitch to begin the bottom of the 12th. Winning pitcher Luis Garcia laid down a sacrifice bunt, and Cesar Hernandez walked.

Jake Peavy relieved Kontos, and Aaron Altherr reached on an error by third baseman Eduardo Nunez to load the bases.

Franco then lined a broken-bat single to center to bring Joseph home.

Garcia (1-0) pitched a scoreless 12th to earn the victory. He combined with five other relievers to blank the Giants over seven innings in all. Starter Phil Klein teamed with the bullpen to retire 19 straight hitters between the fourth and the 10th.

Giants starter Johnny Cueto carried a 4-0 lead into the seventh but surrendered consecutive homers to Howard and Rupp with one out, Franco's game-tying single with two down in the eighth.

Cueto, winless in his past four starts, allowed four runs and seven hits while striking out 10 and walking one in 7 2/3 innings. The strikeout total was his second highest of the season, and he recorded the 12th double-digit strikeout game of his career.

Klein, called up from Triple-A Lehigh Valley when Wednesday's announced starter, Aaron Nola, went on the disabled list with a strained right elbow, took a no-decision in his first major league start of the season. He went five innings and allowed four runs and eight hits while striking out three and walking one.

San Francisco's Denard Span opened the game with a bloop double to center, and advanced to third on Angel Pagan's single. Pagan stole second and with one out Posey grounded a single up the middle, scoring both runners.

The Giants made it 4-0 in the third. Hunter Pence led off with a single, and Posey blasted an RBI double off the center field fence. Posey took third on an infield out and scored on a sacrifice fly by Brandon Belt.

Howard hit a first-pitch fastball from Cueto for his homer in the seventh, his 15th of the year, and Rupp followed by hitting a first-pitch slider over the center field fence. Rupp now has 12 homers this season.

Cueto issued a one-out walk to Jimmy Paredes in the eighth, and Hernandez followed with a single. Altherr then appeared to have legged out an infield single, but he was ruled out on a replay review, leaving runners at second and third with two outs.

Franco lined his two-run single to right, also on a first-pitch fastball, to forge a 4-4 tie.

NOTES: Phillies RHP Aaron Nola said before the game he first began to feel unusual discomfort in his right elbow during his start in Atlanta last Thursday, and after a bullpen session Sunday informed trainer Scott Sheridan of the problem. Nola underwent an MRI Wednesday, and it revealed a strain. Manager Pete Mackanin said it is possible Nola will miss the rest of the season, but Nola said he would like to return before the end. Mackanin added that it was "a good, solid guess" to say RHP Jake Thompson, 11-5 with a 2.05 ERA at Triple-A Lehigh Valley, will be recalled soon. ... Phillies RHP Jeanmar Gomez went on paternity leave, and the team recalled RHP Michael Mariot from Lehigh Valley. Mackanin said Gomez's wife was expected to have induced labor Wednesday, and that the reliever should be available for Thursday's game against the Giants.