SAN FRANCISCO -- The San Francisco Giants scored all of seven runs in three games over the weekend in St. Louis and only one over the two games they lost to end the series. They lost the finale Sunday 9-0.
On Monday night, the Giants looked like a different team entirely -- and bouncing back was crucial for a club hoping to stay in the playoff chase.
"Right now we are under fire in a pennant race," San Francisco third baseman Pablo Sandoval said. "Forget the pennant race. We need to win games right now."
Aubrey Huff added a solo homer leading off the eighth. Huff, Pat Burrell and Freddy Sanchez all doubled in runs in the Giants' five-run first to knock Edinson Volquez (3-2) out after 2/3 of an inning for the shortest start of his career. Sanchez finished with a season-high four hits.
Cain (10-10) retired the final 14 batters he faced and struck out the side in order in the seventh. He allowed two runs on five hits in eight innings, struck out seven and walked one.
"It's a definite momentum builder for us," Cain said. "We had a bad road trip, not something we wanted. It put us in a bit of a bind. We've got a couple people we're chasing."
The Giants trail the first-place Padres by 5 1/2 games in the National League West.
Huff hit a two-run double off the center-field wall after Torres drew a leadoff walk and Buster Posey reached on an infield single. Burrell followed with a double to score Huff, prompting a mound visit by Reds pitching coach Bryan Price. Volquez threw a wild pitch two pitches later that sent Burrell to third. After Jose Guillen struck out, Sandoval hit an RBI single. Juan Uribe walked and Sanchez doubled home Sandoval.
San Francisco batted around in the first and Volquez was done after walking Torres for a second time in the inning on his 39th pitch. Jordan Smith relieved and struck out Posey.
"It's not dead arm; it's a poor command of the strike zone," Reds manager Dusty Baker said. "He's either walking people or finding the heart of the plate. His changeup and breaking ball, those balls are up in the heart of the plate. You get the ball up in the heart of the plate, these are big league hitters, they're going to hit them."
The Giants' five-run first inning marked their biggest initial inning since scoring six in the first against the Mets on June 2, 2008, at AT&T Park. Torres became the first San Francisco Giant to draw two walks in a first inning, according to the Elias Sports Bureau.
Sandoval had a two-run double in the eighth for his third hit, then scored on Sanchez's groundout. Javier Lopez pitched a perfect ninth, as the final 17 Reds were retired in order.
The NL Central-leading Reds, wrapping up a nine-game West Coast swing at AT&T Park, had won eight of their previous nine and 12 of 16 but couldn't manage much against Cain after falling behind right away. Cain threw a season-high 125 pitches.
Edmonds left the game in the top of the sixth with a strained right oblique and could be headed for the disabled list. He was hurt on a swing and a miss on the fourth pitch he saw from Cain. Edmonds grimaced on his follow through and was lifted for pinch-hitter Drew Stubbs.
"This has been an ongoing deal. It's been sore the last week, two weeks," Edmonds said. "Not playing much, I thought it was going to get better. I guess it have me a false sense of security."
Nix sprained his left ankle while beating out an infield single in the third. Nix came around to score on Rolen's hit, then was replaced in the bottom half of the inning by Chris Heisey.
The Giants could use some momentum. They have lost their last three series, all to contenders, so this is another key set against a top team.
"We're by no means out of this thing," Huff said. "We've got to go out, breathe and relax and play baseball."
New outfielder Cody Ross joined the Giants a day after he was awarded to them on a waiver claim from the Florida Marlins. Ross came in as a defensive replacement in center field in the top of the seventh to make his San Francisco debut.
Former Giants managing partner Peter Magowan stopped by to see Baker in the visitor's clubhouse and the two shook hands, apparently past the rift that led to Baker leaving to manage the Cubs following San Francisco's runner-up World Series season of 2002.
"You can only carry stuff around for so long," said Baker, who appreciated the goodwill gesture.
The two hadn't seen each other in more than two years, although they exchanged letters. Magowan retired from his ownership duties in September 2008 and said Baker wrote him a thoughtful letter at the time.
Volquez pitched one inning in his previous short outing on June 1, 2009, at St. Louis. ... The Giants have won eight of Cain's past nine home starts. ... A moment of silence was held and a highlight clip shown for Bobby Thomson, the former New York Giant who died Aug. 16 at age 86. He is famous for his "Shot Heard 'Round the World" in 1951. ... The first-pitch temperature was 75 degrees, a rare warm summer evening here.