SAN DIEGO — The Giants were not built to bludgeon opponents. There will be nights this season when a quality pitcher will make roadkill out of them.

Throw in struggling No. 5 starter Todd Wellemeyer and some of manager Bruce Bochy's oft-lamented buzzard's luck Wednesday afternoon, and it was practically impossible for the Giants to peel themselves off the asphalt.

Their 5-2 loss to Jon Garland and the Padres finished off a three-game sweep at Petco Park and a road trip in which they were flattened while losing five of six.

It wasn't their day or their week. Now they have to prove it still could be their season. They'll play host to the Cardinals, Phillies and Rockies — three of last year's four NL playoff teams — on a nine-game homestand that begins Friday.

"We've been through this before," Bochy said. "We have to show this is a tough and resilient club. This is not something we thought we'd go through. But we are, and we have to handle it."

The Giants ceded first place to the Padres in the NL West, and the Giants' chest-pounding confidence is gone after a roaring start.

Leave it to Bochy to provide a bit of gallows humor, though. He pointed out that the Giants did better on their April swing to the Southland than last year, when they were 0-6 at Dodger Stadium and Petco.

Maybe it won't be difficult for the Giants to shake off this series. After all, it's hard for their offense to perform worse than it did while scoring five runs in a four-game losing streak. They are 1-for-30 with runners in scoring position over that span; the lone hit was Pablo Sandoval's infield dribbler Tuesday.

The Giants benefited from very few breaks here, too. And when they received a gift, as when Eugenio Velez got a favorable call after trying to check his swing in the eighth inning, the result turned out even worse. Instead of merely striking out, Velez lined into a double play on the next pitch.

"What can go wrong will," Bochy said. "That was the case in this series."

Bochy was critical of John Bowker for getting doubled off with the club trailing by four in the late innings. Bowker is hitting .189 after a huge spring; he was dropped to eighth in the lineup, one of several signs he hasn't gained the manager's confidence.

Bowker was robbed of an odd single in the third inning, though. He hit a ground ball down the first-base line that umpire Scott Barry ruled foul even though replays clearly showed it hit the base.

Bochy didn't leave the dugout to argue because he had a bad view from the dugout. Left unsaid by the manager: Neither Bowker nor first base coach Roberto Kelly raised a ruckus to the umpire.

"The call at first base . . . I've gotta get out there," Bochy said. "How that is missed, I don't know."

The Padres weren't just the benefactors of a flat and unlucky opponent, though. They were fleet in the field and created their own breaks. Tony Gwynn Jr. made a full-extension dive to take extra bases away from Sandoval in the sixth inning.

Sandoval got revenge with a 421-foot home run in his final at-bat, although it was a solo shot. The Panda is heating up, but he hasn't gotten many RBI opportunities since leadoff man Aaron Rowand went on the disabled list.

Nate Schierholtz accounted for the Giants' other run. He got jammed on a 3-2 pitch from Garland, but the Padres had their infield back, and Juan Uribe scored on the groundout to first.

Before Uribe's run, the Giants had stranded nine consecutive runners who reached third base.

If they have a similar streak against the NL's best, they could be roadkill in their own park.