PHILADELPHIA(AP) After a sensational and surprising debut with San Francisco, Brad Penny kept his eyes on the Red Sox game on TV as he dressed.

''Those are my buddies over there,'' he said. ''I love all those guys.''

Penny would still be with Boston if he pitched like he did against Philadelphia on Wednesday night. He threw five-hit ball over eight shutout innings in his first start with the Giants, leading the NL wild-card contenders to a 4-0 win over the Phillies.

''It's more than we expected, but I just think this guy was on a mission tonight and it showed,'' Giants manager Bruce Bochy said.

Penny (1-0) was back in his old All-Star form in his first outing since he was released last week by Boston. Penny went 7-8 with a 5.61 ERA this season - including 1-6 in his last 11 starts. Penny could be a huge boost to San Francisco's NL wild-card push if he can pitch like this the rest of September.''

''Some things are hard to explain,'' Bochy said of Penny's Boston collapse, ''and that's one of them.''

Penny's lone jam came in the fifth inning when the first two batters reached base. He got All-Star Raul Ibanez to fly out, and escaped the inning without any further damage.

Ibanez, whose torrid first half got him voted an NL All-Star starter, continued his dreadful second-half slide. He went 0 for 3 and has only 10 hits in his last 75 at-bats. He hit 10 homers in May.

Still, no one in the World Series champion Phillies lineup did much of anything against a suddenly-effective Penny.

The Red Sox might be nipping at the Yankees in the AL East if the righty pitched like this the last two months. It was Penny's longest outing in 28 starts this season and he nearly tossed his first complete game in three years.

''This is what you put a uniform on for, to get into the playoffs and play in the World Series,'' Penny said.

Penny was clocked at 97 mph in the first inning and his fastball remained in the mid-90s over 102 pitches for his first win since July 24.

Penny said he felt no nerves as he took the mound for the first time since Aug. 21. His explanations for his performances in Boston was an odd one.

''A lot of those foul balls to first base that they catch for outs are foul balls in Fenway because there's no foul territory,'' Penny said. ''It's an extended at-bat, and who knows what could happen? Plus it was the Yankees. There's not a lineup better than the Yankees in baseball.''

Juan Uribe and Aaron Rowand each homered for the Giants, who won their 73rd game surpassing last season's total. The Giants trailed Colorado by 1 game in the wild-card race entering Wednesday night.

J.A. Happ (10-4) lost his second straight start for the Phillies.

Phillies manager Charlie Manuel said before the game the Giants were ''full of effort and energy'' and could be a dangerous team down the stretch. Tim Lincecum and Matt Cain give the Giants perhaps the best 1-2 starters in baseball and having Penny return to the form that saw him twice win 16 games with Los Angeles would bolster their playoff chances.

Jeremy Affeldt pitched a perfect ninth to close out the five-hitter.

Happ, a leading candidate for NL rookie of the year, allowed four runs and eight hits in six innings. After a one-out walk in the sixth, Uribe hit a 1-2 pitch into the left field seats for his ninth homer that made it 3-0. Rowand, a former Phillie, followed with his 13th homer on the next pitch to help San Francisco go back-to-back for the fourth time this season.

The Giants took a 1-0 lead in the fifth when Andres Torres hit the eighth straight fastball of the at-bat up the middle for a two-out RBI single.

Happ was thwarted in his bid to become the first Phillies rookie to win 11 games since Bob Walk in 1980. The four runs were the most he's allowed in a game in his last seven starts and only the fourth time in 19 starts this season he's allowed four or more runs.

The Phillies were shutout for the fifth time this season.

''We have trouble manufacturing runs,'' Manuel said. ''If the right guys don't get on base and we don't run, we have a tough time scoring.''

NOTES: The Giants purchased the contracts of LHP Dan Runzler and C Buster Posey from Triple-A Fresno. ... RHP Kyle Drabek and OF Michael Taylor are Philadelphia's winners of the Paul Owens Award for the best pitcher and player in the Phillies minor league system for 2008. Drabek went a combined 12-3 with a 3.19 ERA in 25 games. Taylor hit a combined .320 with 28 doubles, five triples, 20 home runs, 84 RBIs and 21 stolen bases. ... Phillies RHP Brett Myers (hip) threw one scoreless inning in a rehab assignment for Triple-A Leigh Valley.