SAN FRANCISCO -AP- Oh, Buster Posey knew all about how long he had gone without a home run."Yeah, I've had a few reminders over the last week or two," Posey said with a chuckle.All that talk about the star catcher's second-half power drought was answered with one mighty swing in a September game that mattered, and his two-run shot helped the San Francisco Giants beat the St. Louis Cardinals 8-2 Friday night in a matchup of playoff contenders. Posey drove in four runs and the Giants stayed four games back of the NL West-leading Los Angeles Dodgers, who won at Arizona. San Francisco maintained its one-game lead over the New York Mets for the league's top wild card, moving three games up on the Cardinals in the wild-card standings.Left-hander Matt Moore (4-4) allowed two runs over five innings, struck out four and walked three while facing the Cardinals for the first time in his career. He won for the fourth time over five starts in his ninth outing since joining San Francisco in a trade with Tampa Bay.Posey was all smiles in the dugout after his fourth-inning drive, his first home run in 185 at-bats and exactly two months -- he last connected on July 16 at San Diego."It was a good feeling," he said.Posey also had a two-run single and followed up his four-hit game Thursday night with three more."It was great to just see him start smiling and laughing after he touched home plate," Brandon Belt said. "It's kind of out of the ordinary with him. He's pretty stone-faced most of the time. When you know what he's capable of doing and when he's had a stretch like he's had, it's good to see."Belt hit a two-run double to highlight San Francisco's six-run third. Posey singled in a pair of runs that inning, when all the runs were unearned off rookie right-hander Luke Weaver (1-3).For the second straight day, Giants manager Bruce Bochy gave his team a late report time to the ballpark and the players went without batting practice. This time, it came on the heels of Thursday's 6-2 victory behindJohnny Cueto's five-hitter."A couple days off the field will serve them well," said Bochy, who is sticking with the same routine for Saturday night's game.It proved the right call again. After a demoralizing three-game sweep by San Diego earlier this week, San Francisco suddenly looks like a playoff team again. The Giants have had World Series-winning seasons in every even year this decade: 2010, `12 and `14.Weaver's night was done after 2 2/3 innings and he is winless in four starts since beating Oakland on Aug. 26. He allowed five hits, struck out four and walked two.Yadier Molina drove in both runs for the Cardinals, including a bases-loaded walk in the fifth."We just have to play better, that's all there is to it," manager Mike Matheny said. "The standings are the standings and we know what they are. You can't run from them, hide from them. The standings say we're right there, so just keep playing the game. That's all it is. Same as always."Denard Span hit eighth for the Giants again after his strong performance, with a two-run single among his two hits in that spot a night earlier.NINTH-INNING DELAYA fan ran on the field in the top of the ninth and a member of security who slid approaching the man had to be helped off the field with an injury.