Snow drove in the go-ahead run in the eighth inning and then dived to his left to stop a sharp grounder in the ninth, leading the Giants over the San Diego Padres 6-5 on Tuesday night.
"We don't need to be concerned with individual things right now," said Snow, who matched his career high with four hits. "We need to get the team on a roll. We need to start winning games and this is a start."
The victory may prove costly, as Giants closer Armando Benitez needed help walking off the field after sustaining a right hamstring strain on the game's final play.
Benitez retired Geoff Blum on a grounder to first with a runner on second to end the game. He pulled up lame two steps before first base while taking the flip from Snow.
"Hopefully he's all right," Giants starter Jason Schmidt said. "He's just starting to get into his groove. You hate to see a setback like that."
Phil Nevin extended his hitting streak to 11 games, pinch-hitting in the eighth and homering off Benitez, a two-run drive that tied it at 5.
Benitez (1-1) blew his second save in six chances but got the win.
Snow, who had three hits in his previous 18 at-bats against Adam Eaton, doubled in the first, singled in the third and tripled home a run in the fifth against the right-hander.
"J.T. does that all the time," Giants pitcher Scott Eyre said.
"He makes big plays and gets big hits. This was a big win to have to comeback like that."
Sweeney also made two errors in the seventh that helped the Giants score three unearned runs.
"It's embarrassing," Sweeney said. "You're supposed to make those plays. I let Adam down. He pitched a great game."
Schmidt took his second straight no-decision after a 131-pitch outing that lasted 6 2/3 innings. He gave up three runs, eight hits and four walks, striking out seven.
Eaton gave up two runs and five hits in six-plus innings.
"Mistakes haunted us," Padres manager Bruce Bochy said. "We didn't get an out when we needed it in the seventh and Otsuka gave Snow too good of a pitch."
Snow said he was jammed on the pitch.
"I just got enough of it to keep it fair," he said.
Sweeney's first home run of the season, a solo shot with one out in the second, put the Padres ahead.
Hernandez tied the game at 2 with his third home run, a solo shot into the right field pavilion.
Pedro Feliz singled home two runs and Ray Durham drove in a run in the seventh as the Giants took advantage of three errors in the inning to forge a 5-3 lead. Ryan Klesko gave the Padres a 3-2 lead with a two-out double in the seventh.
Outfielder Barry Bonds was presented the 2004 player of the year award by the local chapter of the BBWAA. ... Felipe Alou earned his 200th win as manager as Giants manager. ... Padres right-hander Tim Redding has given up 10 hits in 23 at-bats to right-handers. ... Sweeney's previous home run also came against Schmidt on Sept. 7 in San Diego. ... Vizquel is 7-for-7 in stolen-base attempts. ... Snow has 18 career triples. ... Alfonzo left the game for precautionary measures with tightness in his left hamstring after hitting in the eighth.