Cain (1-2) led the NL with an opponents' batting average of .109 (12-for-110) and ranked third with a 1.54 ERA entering the game. Those numbers lost their glitter as he allowed four second-inning runs and vanished during Philadelphia's five-run fourth.
The 22-year-old right-hander sensed nothing wrong as he approached his first pitch.
"I felt good coming out of the bullpen, actually," Cain said, adding that he encountered no physical problems. "I got in the game and got behind a lot of guys. I got them into great hitting counts and they took advantage of it, big-time."
Giants manager Bruce Bochy concurred.
"You saw what happened," Bochy said. "He had good stuff. He just had trouble getting the ball where he wanted."
Cain may have been due for a subpar performance after such sustained success.
"The kid has been throwing so well," Bochy said, absolving Cain from blame.
But Cain, whose ERA rose to 3.08, dismissed this kind of chatter.
"It doesn't matter if things are going great or going bad. To have that outing altogether isn't good, to not give your team a chance early," he said.
Cain's truncated effort had a definite effect. Because the bullpen had to work overtime, shortly after logging four innings Monday and 5 2/3 more Tuesday, Bochy said that the Giants likely will summon a reliever Friday from Triple-A Fresno as a temporary reinforcement. Possibilities include Pat Misch, Scott Munter and Billy Sadler.
Among the game's more redeeming aspects from the Giants' perspective was that fewer folks than usual noticed it, since enough other stuff was happening to deflect attention. Across the Bay, the Golden State Warriors defeated the Dallas Mavericks to advance to the second round of the NBA playoffs. Sitting through rain and mist for much of the evening, the widely scattered paid crowd of 33,466 saved some of their loudest cheers for Warriors updates on the main scoreboard.
The Giants made their biggest news of the day before the game, when they all but officially declared that Tim Lincecum, their top pitching prospect, would ascend from Triple-A Fresno in time to start Sunday's series finale against Philadelphia. Lincecum will replace Russ Ortiz, who went on the 15-day disabled list with an injured right elbow. It's conceivable that the reliever the Giants promote will make a quick U-turn to the Minors to accommodate Lincecum.
The Giants' performance included some promising elements. Switching positions in the batting order as expected, No. 2 hitter Randy Winn continued his surge by going 3-for-5 with two doubles, two runs scored and an RBI. Omar Vizquel, who complained before the game about his inability to drive pitches, did just that while batting eighth with a bases-loaded, two-run double off Phillies starter Adam Eaton (3-2) that fueled the Giants' big sixth.
Facing reliever Ryan Madson, Kevin Frandsen contributed a run-scoring groundout before Winn lined an RBI double off the right-field wall. Winn scored on Eliezer Alfonzo's triple, a sinking liner to center field that skipped past a diving Aaron Rowand.
Walks to Ray Durham and Vizquel enabled the Giants to bring the potential go-ahead run to the plate with two outs in the seventh, but the magic had dissolved.
"They fought hard to get back in it," Bochy said. "That's a great sign."