SAN DIEGO -- Paradoxical as it sounds, the more Matt Cain is denied victory, the more he triumphs.

The cruel joke that has been Cain's 2007 season continued on Friday night, as the San Diego Padres triumphed, 4-3, on Scott Hairston's second home run of the game -- a one-out drive to left field in the 10th inning.

Constantly victimized by poor run support and faulty relief pitching, Cain watched a 3-0 lead dissolve in the eighth inning when Vinnie Chulk surrendered Hairston's three-run homer. San Diego settled matters two innings later, when Hairston deposited Jack Taschner's 3-2 pitch barely over the left-field wall.

By striking out a season-high 11, allowing only three hits entering the eighth and outclassing future Hall of Famer Greg Maddux, Cain appeared destined to collect only his fourth victory of the season and his first since July 4.

He left PETCO Park with nothing except his dignity, patience and grace -- which, for those able to view the big picture, transcended yet another frustrating defeat for the Giants.

"It's tough to look at my record, but it comes back down to the team. It's just not about individual performance," said Cain, who is 3-12 despite a decent 3.93 ERA. "If we give up the runs and I don't get the decision and we come back and win, it doesn't matter, because we won as a team. The big thing is to keep winning and do what we've been doing the past two weeks."

Center fielder Dave Roberts has noticed that the 22-year-old Cain has handled adversity with a maturity beyond his years.

"I know the way he's carrying himself," said Roberts, who carried the Giants' offense by going 4-for-5 with three doubles and two RBIs. "He's not bitter toward anybody and still respectful of his teammates and the game. I know he's hurting; I know he's such a competitor. He's being forced to grow up a lot quicker than you'd like it."

Blameless as Cain was, he actually faulted himself for the Padres' comeback. "I kind of started it off with that 0-2 pitch down the middle to Blum," Cain said.

That would be Geoff Blum, who singled to open the eighth. Cain, who threw 111 pitches, disappeared after Rob Mackowiak doubled Blum to third.

Chulk coaxed Mike Cameron's foul popout to first base, but Hairston, acquired in a July 27 trade from Arizona, slammed a first-pitch slider for his first home run for the Padres.

Chulk wanted to throw the pitch low and outside, but he flung it with insufficient snap.

"Unfortunately, it spun out of my hand," he said. "I kind of knew when I threw it that it wasn't where I wanted it to be. If it's down and away where I wanted it, either he swings over it or he grounds it to short."

This echoed an April 28 game at Arizona, where Cain bequeathed a 4-1 lead to the bullpen after allowing one hit through six innings. The D-backs rallied for four seventh-inning runs, three coming on Hairston's pinch-hit homer off Chulk.

"Any way you can count it, he's been worked over a lot of different ways," Chulk said of Cain, who has received more than two runs in only eight of 22 starts and has seen the bullpen blow four leads behind him.

The Giants desperately tried to reclaim the lead in the ninth as Mark Sweeney, who drew a two-out walk, was easily thrown out at home as he attempted to score on Roberts' double to right field off Trevor Hoffman.

Asked whether he considered using the fleet Rajai Davis to run for Sweeney, Giants manager Bruce Bochy explained, "[Hoffman] is tough to run on. I didn't want to use another player at that point. Sweeney's not the slowest guy in the world, and he's not as fast as Davis, no question. But I didn't feel that was the appropriate time to use him."

Leery of exhausting his bench, Bochy did insert Davis in left field with Taschner (2-1) as part of a double-switch in the 10th. It was Davis who gathered himself under Hairston's towering drive and leaped for the ball in vain.

Taschner said that the fateful pitch was a fastball. "I tried to get it over the corner," he said. "I didn't."