By Jeremy Kahn

AP photo: San Francisco Giants Hunter Pence gets a fifth inning single, Pence also had a double in the ball game against the Washington Nationals on Saturday at AT&T Park

SAN FRANCISCO-This was a win that the San Francisco Giants most definitely needed to win after the rut that they have been in since the All-Star break.

Joe Panik hit a sacrifice fly in the bottom of the seventh inning that scored Buster Posey from third base, as the Giants came back from a 3-0 deficit to defeat the Washington Nationals 5-3 before a crowd of 41,743, the 460th consecutive regular season sellout at AT&T Park.

The Giants added another run in the inning, as Trevor Brown drew a pinch-hit bases loaded walk to Hunter Pence. Posey singled got the seventh inning rally started, as he singled then Pence walked and then Brandon Belt singled to load the bases to bring up Panik.

Anthony Rendon got the Nationals on the board in the top of the second inning, as he smashed a two-run home run off of Jake Peavy into the left field seats.

Danny Espinosa gave the Nationals a 3-0 lead in the top of the third inning, as he doubled in Ryan Zimmerman, who led off the inning with a single just prior to Espinosa’s double.

Finally in the bottom of the fourth inning, the Giants got Nationals pitcher Reynaldo Lopez, as they scored three runs to tie up the game.

Brandon Belt led off the inning with a walk, then Panik singled, then after Gregor Blanco struck out looking and then Mac Williamson, pinch hitting for Peavy walked to load the bases to bring up newly acquired Eduardo Nunez, who was acquired from the Minnesota Twins on Thursday night. Nunez delivered, as he hit a two-run double to score Belt and Panik.

Angel Pagan then tied up the game, as he grounded out to Zimmerman to score Williamson, who dove in head first to cross the plate and to tie up the game.

Peavy went four innings, allowing three runs on six hits, walking just one and striking out seven. The home run to Rendon was the sixth home run that Peavy allowed since the All-Star break.

In his return after missing 48 games with a right hamstring injury, Pence went 1-for-3 with a run scored, a double and a walk.

Six different relievers pitched the final five innings, as they allowed three hits, walking just one and striking out three.

The victory went to Derek Law, who pitched one inning and struck out one to pickup his fourth win of the season. Santiago Casilla pitched a perfect ninth inning to pickup his 23rd save of the season.

Former Giants pitcher Yusmeiro Petit picked up the loss for the Nationals, as he allowed two runs on four hits, while walking two and striking out one. It was the first run that Petit allowed in his last seven appearances.

Brandon Belt drew three walks on the afternoon, and it was the sixth time this season that he walked three or more times in a game. Belt came into the game with the fourth most walks in the National League.