PHILADELPHIA -- The San Diego Padres had just the right guy on the mound Sunday afternoon at Citizens Bank Park.

Who better than a pitcher with the nickname "Big Game James?"

The Padres, riding a three-game skid and losers of five of their last six, finally took down the Philadelphia Phillies with a 9-4 win behind seven dominant innings from right-hander James Shields.

"We're trying to win every game right now," Shields said. "We have to win as many games as we possibly can. But to be able to shut them down and not get swept is nice."

It also helped that after scoring just four runs over the first two games of the series, San Diego broke out early and late behind 16 hits, including three home runs.

"I think the whole offense should feel pretty good about themselves today," Padres interim manager Pat Murphy said. "If we want to win, it's about our big guys coming up big. They did today and that really set everything up."

San Diego (63-67), which came into the game 0-5 this season against Philadelphia (52-79), got homers from right fielder Matt Kemp, left fielder Justin Upton and third baseman Yangervis Solarte, while Shields (10-6) knew just what to do with it, allowing one run and striking out eight over his seven frames.

He also chipped in at the plate with an RBI single.

"I'm not really worried about RBIs per se, I'm more worried about scoring more runs while I'm pitching," Shields said. "I was glad I was able to help myself out today."

The long balls by Kemp and Upton came early against right-hander Alec Asher (0-1), who was making his major-league debut, and San Diego never looked back by breaking it open late.

"Definitely had some nerves," Asher said. "Tried to calm down and focus on pitching and winning the ballgame.

"I thought I was all right. I made a couple of bad pitches that I paid for. But I mean, I wouldn't take back the experience. It was great. You obviously want to win. But you take the experience and learn from it."

Despite the loss, Philadelphia is 18-5-2 in 25 series against the Padres since 2004.

"On the minus side, we lost the game. But on the positive side, we won the series," Phillies interim manager Pete Mackanin said. "Asher, first appearance in the major leagues. I liked him. I liked his stuff, I liked his approach. He got behind too often, he left the ball up the in zone a little bit too often. So it's understandable when a guy's got his first major-league appearance in front of the home (fans)."

San Diego raced out of the chute Sunday when Kemp hit a bullet into the left-field seats for a two-run homer in the top of the first inning.

The Phillies got one back in the bottom of the second inning on an opposite-field solo shot by catcher Cameron Rupp, but the Padres snagged it right back the next inning when Upton skied a solo homer of his own to left-center field.

"Today the ball was flying out big time," Shields said. "We were hitting pop flies that were going to the warning track and so were they. It was a tough day today but it was nice to have a little lead there at the beginning."

With runners on first and third and two outs in the top of the sixth inning, Shields helped his cause with a bloop single up the middle to make it 4-1 and knock Asher out of the game.

Asher, acquired in the July 31 trade that sent Cole Hamels to the Texas Rangers, went 5 2/3 innings, allowing four runs (all earned) on eight hits while striking out three.

"What I learned is, don't miss your spots," Asher said. "They are good and they are here for a reason."

Shields, who entered with the fifth-most strikeouts in the National League, increased his season total to 184. With the victory, he's now amassed double-digit wins in nine consecutive seasons.

San Diego tacked on in the seventh, eighth and ninth innings against Philadelphia relief pitching to put the game out of reach.

"We can't just count on our hitters every night to score runs for us," Shields said. "We've got to pitch and play defense."

NOTES: The Phillies claimed LHP Ken Roberts off waivers from the Colorado Rockies and optioned him to Triple-A Lehigh Valley. ... Padres RHP James Shields hit eighth, ahead of OF Travis Jankowski. ... The Phillies open a six-game road trip Monday, with a three-game series against the New York Mets. Philadelphia's probable starters are RHP Jerad Eickhoff (1-1, 2.25 ERA), RHP Aaron Harang (5-14, 4.79 ERA) and RHP Aaron Nola (5-1, 3.26 ERA). ... The Padres open an 11-game homestand Monday, with a three-game series against the Texas Rangers. San Diego's probable starters are RHP Tyson Ross (9-9, 3.42 ERA), RHP Andrew Cashner (5-13, 4.06 ERA) and RHP Ian Kennedy (8-12, 3.94 ERA).