As has been the case so far this season, even success for the Pittsburgh Pirates has been hard to celebrate.
Cain allowed only a single to the opposing pitcher in the sixth inning during a near-perfect performance Friday, throwing his third career one-hitter to lead the Giants past the Pirates 5-0 in San Francisco's home opener.
"You think about, it's like, 'Man, the pitcher stood in his way for a perfect game,'" a somber McDonald said. "But it happens."
Cain (1-0) struck out 11 and permitted just the lone runner in the fifth shutout and 14th complete game of his career. McDonald, a career .069 hitter coming into the game, lined a sharp single to left field with two outs in the sixth inning.
Fans in the sellout crowd of 41,138 jumped to their feet to give Cain a loud ovation on a sun-touched day along San Francisco Bay. The hit stood over the final 10 outs and remained the only blemish on Cain's remarkable afternoon.
Leave it to another pitcher to prevent perfection.
"That's the beauty of the game," Pirates manager Clint Hurdle said. "A swinging bat is a dangerous bat. I should've hit him higher in the lineup."
San Francisco backed the run-starved Cain for the 2012 home debut.
Aubrey Huff homered and drove in three runs as the Giants returned from a rough 2-4 road trip, getting swept at Arizona and taking two of three at Colorado. Buster Posey also hit an RBI double in his first regular-season game at AT&T Park since his season-ending injury in a collision at the plate with the Marlins' Scott Cousins last May 25.
The Giants celebrated their 1962 World Series team and a large cast of Hall of Famers with an impressive day—blue skies and plenty of sun, too, after a huge rain and lightning storm overnight and into Friday morning threatened to make the festivities a mess.
Instead, Cain made the day sparkle even more.
Cain, who has long been the team's hard-luck ace because of a lack of run support, went the distance in throwing 106 pitches—even more important considering bearded closer Brian Wilson wasn't available after he worked a 32-pitch ninth inning a day earlier in a 4-2 win at Colorado. The game took only 2 hours, 10 minutes.
Pitching 11 days after signing a $127.5 million, six-year contract, Cain worked ahead all afternoon and faced only one three-ball count while retiring the first 17 batters in order until McDonald's hit.
"I was definitely aware of it but I'm thinking there, 'I'm behind in the count 2-1 but I'm throwing something to the outer third of the plate," Cain said. "He put a good swing on it. He did his job. He can hit."
McDonald (0-1) produced his seventh career hit but Pittsburgh dropped its fourth straight game after being swept at Dodger Stadium. He allowed three runs and six hits in 5 2-3 innings, struck out one and walked three.
But as a pitcher, he was practically apologizing for his hit.
"He'd have been in the history books," McDonald said. "If that was me, I'd be like, 'Man, the pitcher got me. That (stinks). But I threw a great game.'"
McDonald couldn't quite say the same.
Huff hit a two-run homer in the eighth. Nate Schierholtz had a pair of singles and drove in a run in the sixth for the Giants, trying to regain the rhythm from the improbable 2010 World Series title team. Pittsburgh, now just 2-5, is just trying to gain any kind of rhythm in what has been a horrid start offensively.
"The pitcher gets the hit off Cain, of all people. Good he was able to get it," said Pirates center fielder Andrew McCutchen, who was 0 for 3. "Guess that's the one positive we can get out of that."
NOTES: Cain's previous shutout came on June 8, 2010, at Cincinnati. ... San Francisco manager Bruce Bochy said Wilson would be ready to go for Saturday night. ... The Giants sold out for the 85th straight time, a streak that began with the final three regular-season games of 2010. ... Garrett Jones played his first game of the season in RF for Pittsburgh. ... The Pirates will need to make a roster move Saturday if Charlie Morton comes off the disabled list to start.
Follow Antonio Gonzalez at: www.twitter.com/agonzalezAP