SAN FRANCISCO (AP) -- Mark Kotsay nearly got away with a gift out in the first inning. Clayton Richard did not get away with two walks, however, and the San Diego Padres couldn't rally from a four-run deficit, losing 7-1 to the San Francisco Giants.
Buster Posey hit a three-run homer, Ryan Vogelsong won for the first time in nearly a month and the Giants opened their longest homestand of the season with the victory.
Kotsay nearly saved a run in the first when it appeared he caught a sinking line drive by Brandon Crawford to end the inning. The call was overturned when the umpires gathered to talk about it.
"When you look at it full speed you can't tell if I catch it or not," Kotsay said. "Three guys made the decision. I was in no way trying to deceive the umpires."
That hit gave the Giants a 4-0 lead and half of the runs were hitters Richard walked.
"That's the thing that gets you," Richard said. "The walks are where we ran into trouble. Later in the game I left the ball up. I didn't have command of anything in the first inning. I eventually made an adjustment but it wasn't quick enough."
Vogelsong, who was facing the Padres for the first time in nearly eight years, allowed one run and four hits over seven innings. The right-hander walked three and struck out six while lowering his ERA to 2.26.
"The guy was an All-Star pitcher last year," Padres manager Bud Black said. "He's a pretty good pitcher."
Yasmani Grandal had two hits for San Diego, which has lost five of seven games to San Francisco this season.
"You always want to play well in the first game of a series," Padres infielder Chase Headley said. "But you're going to have games like this. It won't matter if we can bounce back."
Posey's third home run in his last 11 games highlighted another stellar night from the Giants' All-Star catcher.
Since going hitless against Pittsburgh on July 7, Posey has been San Francisco's best hitter. He went 3-for-4 against San Diego and is batting .512 over his last 11 games.
"He has plate discipline," Richard said. "He comes to the plate knowing what he's looking for and if he gets it, he can hurt you."
Yonder Alonso's sacrifice fly in the fourth inning produced the Padres' only run.
Richard (7-11) gave up seven runs over five innings in his shortest outing of the season. Three of his losses have been against the Giants.
San Diego had a rough night all around.
The Padres lost to the Giants for the 16th time in the past 21 games between the clubs and lost center fielder Alexi Amarista to a left thumb injury.
Amarista was hurt while sliding into the bag after stealing second base in the fifth. He stayed in the game and completed the inning before being replaced by Jesus Guzman.
Black said Amarista was going to be fine.
NOTES: San Diego OF Carlos Quentin was rested a day after agreeing to a $27 million, 3-year contract. ... Padres RHP Tim Stauffer (strained right elbow) threw his first bullpen session since going on the DL on May 15 and is scheduled for a second session Wednesday. If he makes it through without a setback, Stauffer will head to Peoria to continue his rehab in the minors. ... Padres OF Cameron Maybin remains day to day because of a sore right wrist but the team is optimistic about his progress. ... San Diego RHP Edinson Volquez takes a 6-7 record into Tuesday's game against San Francisco LHP Madison Bumgarner (11-6).