Minutes after the game, the Giants announced the acquisition of Sanchez, who sat out the series with an injured left knee, in exchange for Minor League left-hander Tim Alderson.
The Giants hope that Sanchez can help generate the offense they lacked against the Pirates, who held them to eight runs in the series. Fortunately for the Giants, they made virtually every run count, especially Wednesday's solitary tally.
Eugenio Velez singled sharply up the middle to open the Giants' uprising against Pirates right-hander Matt Capps. Juan Uribe's sacrifice bunt moved Velez to second base before pinch-hitter Fred Lewis struck out. Andres Torres prolonged the inning with a walk.
Up came Winn, who grounded Capps' first pitch down the first-base line past a diving Steve Pearce to score Velez easily. Winn happens to be San Francisco's leading hitter with runners in scoring position, owning a .358 average (29-for-81) in such instances.
"I thought Torres did a good job drawing the walk and setting up that situation," Giants manager Bruce Bochy said. "But you like it when Randy's up there with the game on the line."
In a sense, the game was on the line in every inning for Matt Cain, since the Giants couldn't score for him. Cain responded with yet another sterling effort, blanking Pittsburgh on three hits through nine innings. He allowed only two Pirates to advance as far as second base and retired 20 of the final 22 batters he faced.
"We won the game because of him, even though he didn't get the win," Bochy said. Brian Wilson struck out two Pirates while pitching the 10th inning to earn the decision.
The Giants' inability to score for Cain prevented him from becoming the Major Leagues' first 13-game winner. Cain was rewarded nevertheless, as he trimmed his ERA from 2.27 to a league-leading 2.12. His ERA in six July starts is 0.94.
Cain, whose fastball reached 96 mph in the ninth inning on AT&T Park's velocity readings, lobbied Bochy to pitch the 10th.
"I said I felt fine," Cain said. "It's a game where you know it's going to be tough, and obviously the way it was going, you have to stay in there the whole way. I tried to tell him that, but it didn't work."
Cain thrived despite striking out only four batters -- a marked contrast with co-ace Tim Lincecum, who struck out 15 Pirates on Monday. Though Cain remains capable of accumulating high strikeout totals, he has gained an appreciation for preserving his valuable 24-year-old arm.
"You're trying to find different ways to get guys out quicker, where maybe you don't have to exert as much energy," Cain said. "It's nice to strike out a lot of guys, but I figured I'd waste a lot of pitches."
Another arm the Giants must try to save is Edgar Renteria's. The shortstop, who turns 34 on Aug. 7, will need surgery after the season ends to remove a bone spur from his right elbow. Renteria made strong throws on a pair of sparkling ninth-inning plays, but Bochy announced that the veteran likely won't play consecutive games when a night game-day game sequence arises.
Meanwhile, Velez continued his bid to stick with the Giants, who face roster moves to accommodate Sanchez and infielder Rich Aurilia, when the latter returns from the disabled list. Velez, who homered and hit an RBI double Tuesday night, is 5-for-10 since his recall Monday from Triple-A Fresno.
"He's got a lot of confidence going," Bochy said of Velez. "That started in Fresno, the way he's been playing, and he brought it up here with him."