SAN FRANCISCO -- Huston Street made it tough on himself. In the end he made it all work out.
Mark Kotsay hit a home run and Yasmani Grandal also drove in a run for the Padres, who had lost four of their previous five games. Everth Cabrera had four hits, walked and stole three bases in five plate appearances.
Street pitched the ninth for his first save since Aug. 10, his 22nd of the season and 200th of his career. His scoreless streak ended at 21 2/3 innings.
"It's a round number but I don't want to finish there," Street said. "It means something because I got the ball authenticated and I don't get that every save. There's a certain sense of accomplishment but there's a lot more to get."
This one wasn't easy.
Pinch hitter Aubrey Huff singled to lead off the ninth. Street got pinch hitter Pablo Sandoval to fly out to right but then walked pinch hitter Hunter Pence and Hector Sanchez to load the bases. Posey grounded out, driving in his 98th run of the season before Ryan Theriot lined out to center field to end it.
"It's wasn't difficult if I don't walk people," Street said. "I walked Pence on four pitches. That's just bad baseball. It's a test and it's never easy."
Xavier Nady, who had two hits, Eli Whiteside, Emmanuel Burriss and Buster Posey each drove in runs for the Giants, who rested their regulars a day after clinching the NL West Division title.
Eric Stults (7-3) worked six-plus innings, allowing three runs on seven hits, to win his sixth in seven decisions. He struck out four and walked one.
"That was fairly typical of what Eric has given us," Padres' manager Bud Black said. "A wide range of velocities and a mix of pitches. I though Huston's stuff was good but he was just a touch rusty. There are a lot of ways to get it done and he got it done."
Yusmeiro Petit made his Giants' debut, allowing two runs on seven hits over 4 2/3 innings. He walked four and struck out one.
"I felt great," Petit said. "It's been three weeks without pitching. I felt a little lost in the first inning but then I was able to do the job."
Clay Hensley (4-4) took the loss after giving up Alonso's hit.
Petit made his first major league since Sept. 6, 2009 when he was with the Arizona Diamondbacks as the Giants had their six-game win streak and seven-game home win streak stopped.
The Padres scored their first run in the second when Theriot threw the ball into left field trying to catch Alexi Amarista off second base following a sacrifice fly.
Nady doubled home a run and Whiteside hit a sacrifice fly to put the Giants up 2-1 in the fourth.
Grandal's single tied it in the fifth and Alonso's hit put San Diego ahead in the seventh.
Burriss hit an infield grounder to score a run in the seventh.
Kotsay hit his pinch hit home run in the eighth. Cabrera followed with a walk, stole second and third and jogged home when Hector Sanchez's throw went into left field.
RHP Tim Lincecum (10-14, 4.91) will start for the Giants when the Arizona Diamondbacks come to town on Tuesday. He was originally scheduled to pitch Sunday. ... The Padres send RHP Edinson Volquez (10-11, 4.31) to the mound against the Los Angeles Dodgers in San Diego on Tuesday. ... Giants OF Francisco Peguero beat out an infield single in the fourth for his first major-league hit. ... Grandal has hit safely in 17 of his last 23 game. ... Kotsay hit his fifth career pinch hit home run. ... Huff has four hits in his last six PH appearances.