SAN FRANCISCO -- Hitting coach Hensley Meulens celebrated his 47th birthday on Monday, but the Giants didn't honor him with much of a present.
San Francisco was shut out in a 6-0 Padres victory at AT&T Park on Monday night as 27-year-old Cuban pitcher Odrisamer Despaigne logged an impressive MLB debut.
The loss marks the Giants' 10th in their past 13 games as they are struggling to recreate the winning baseball that staked them to the best record in the bigs less than two weeks ago.
San Francisco is 32-10 (.762) this season when scoring the first run of the game, but that rarely happens with Cain on the mound. The Padres became the seventh of 12 opponents to draw first blood against the Giants' right hander.
Cain, who ceded a season-high eight runs his last outing in Chicago, allowed another six to cross the plate on Monday.
After the Dodgers lost 5-3 to the Royals earlier in the day, the Giants still hold a 4-game division lead over LA.
Starting pitcher report
Cain remains six wins shy of 100 for his career, but he is officially having a down year as he failed to record a quality start for the ninth time in 12 assignments.
He hasn't beat the Padres at AT&T Park since April 2009.
Breaks have been few and far between for Cain this season, and just when it seemed that a three-minute replay delay would erase a three-run home run by Yasmani Grandal, Tommy Medica roped a two-run double down the left field line to punctuate a three-run fourth inning.
Grandal connected on an 86-mph changeup and sent it high and deep to right. It would have been close to a home run atop Levi's Landing, but a Giants fan reached out and caught it in his hat. Hunter Pence immediately reacted and Bruce Bochy sauntered onto the field to argue after Grandal was initially awarded a home run.
Upon the reversal, Padres manager Bud Black came barreling out of the dugout and immediately received his first ejection of the season.
Cain used 37 total pitches to get through the first three innings, but expended 29 to get out of the fourth alone. He locked in after the tough inning, using nine pitches in the fifth, 11 in the sixth and six in the seventh before things fell apart in the eighth. Three consecutive singles coaxed Bochy from the dugout and sent Cain -- eyes on his toes -- toward the showers.
Cain's final line: 7 1/3 IP, 7 H, 6 ER, BB, 7 K, 102 P, L.
Javier Lopez took over for Cain with a runner on third and one out in the eighth inning and allowed an RBI double to former Athletic Seth Smith, pinning Cain with his sixth earned run.
Juan Gutierrez entered for Lopez and finished off the three-run eighth by inducing a pair of flyouts. And Yusmeiro Petit handled the ninth without incident.
At the plate
You would have expected some offensive spark from the Giants on this night. They honored late Hall-of-Famer Tony Gwynn -- who Bochy called "one of the best hitters of all time" -- before the game and celebrated their hitting coach's birthday. But the 10-game homestand opened with a goose egg.
Despaigne became the second Cuban-born player ever to pitch for the Padres (16 2004 outings for Eddie Oropesa) and he started by economically expending 29 pitches to get through three innings of perfect ball.
The Giants waited until the fourth inning to collect their first baserunner, when Hunter Pence smacked a double to right-center field.
Brandon Crawford, Gregor Blanco and Michael Morse represented the Giants' only other baserunners against Despaigne, who departed after seven innings of four-hit ball with one strikeout and no walks.
It's the second time the Giants have been shut out with Cain on the mound this year. The team has provided two or fewer runs of support in nine of his 12 starts.
In the field
Brandon Crawford's throw to first base on Tommy Medica's seventh-inning ground ball just pulled Michael Morse off the bag for his 11th error of the season. Crawford committed his 10th error on Sunday in Arizona.
Crawford's mistake was erased when Joe Panik, making his second career MLB start and first at AT&T Park, started a 4-6-3 double play on the next pitch. Panik handled all four chances that came his way.
Hunter Pence made the team's second error when Sandoval couldn't block his short-hopped throw in the eighth inning. It allowed the Padres' fifth run to score and put their sixth run on third base with one out.
Sandoval, though, flashed his leather on a pair of hard line drives by Carlos Quentin and Will Venable, snagging Quentin's off the turf in the fourth and skying high to his backhand to snare Venable's in the fifth.
The Giants announced a paid attendance of 41,360, which offered standing ovations when Panik stepped to the plate for the first time and when Barry Bonds -- watching from next to the Giants dugout -- was shown waving to the AT&T Park crowd on the jumbotron. The Giants' MLB-leading regular season sellout streak reached 285 games.
The Padres and Giants continue their three-game series Tuesday night at AT&T Park with right-handers Jesse Hahn (2-1, 2.16) and Tim Hudson (7-3, 2.39) on the mound. The action starts with Giants Pregame Live on Comcast SportsNet Bay Area at 6:30 p.m.