SAN DIEGO -- Madison Bumgarner was feeling pretty lucky on Wednesday.
"I didn't throw very well," Bumgarner said. "Defense picked me up and offense picked me up, too. It was nice to sneak a win out of it."
Blanco scored twice for the Giants, who have won eight of 10 overall and 14 of their last 19 against the Padres, who have the worst record in the majors.
Bumgarner allowed four runs and seven hits, struck out four and walked four.
"I didn't have command of anything today, it seemed like," he said. "It just seemed like I was having to constantly make adjustments to try to get the ball where I wanted it. I had a hard time doing it pretty much the whole game."
Trailing 6-3, the Padres loaded the bases with no outs in the sixth but scored only one run. Carlos Quentin and Jesus Guzman singled and Logan Forsythe walked before Bumgarner struck out Nick Hundley, allowed Everth Cabrera's run-scoring groundout and then got pinch-hitter Yonder Alonso to foul out to third.
"We had a couple of chances but couldn't get the big hit," Padres manager Bud Black said.
The Padres pulled to 6-5 in the seventh when Chris Denorfia hit a leadoff triple off Clay Hensley and scored on Chase Headley's groundout. They had a runner on third with two outs in the eighth before Javier Lopez relieved Hensley and got pinch-hitter Mark Kotsay to ground out.
Richard went 5 2/3 innings, allowing six runs -- four earned -- and matching his season high by allowing 10 hits.
The Giants jumped on Richard for three runs and five hits in the first inning. Blanco and Ryan Theriot opened with singles and Melky Cabrera bounced a double over the fence in left to bring in Blanco. Buster Posey followed with a sacrifice fly and Cabrera scored on a passed ball.
"The only ball they hit hard in the first inning was Cabrera's," Hundley said. "I don't think there were a whole lot of adjustments."
The Padres were 1 for 11 with runners in scoring position. Hundley stranded five runners, including three in scoring position.
"The frustration lies with me," said Hundley, who's hitting just .164. "It's nobody else's fault but mine. I had a lot of chances but I'm not getting it done. If I do my job today, we win."
San Diego scored twice in the bottom of the first, collecting three extra-base hits against Bumgarner. Denorfia hit a leadoff double to right and scored on Headley's double to right. After Headley was thrown out at third trying to advance on Quentin's grounder to shortstop, Guzman tripled over right fielder Blanco's head to bring in Quentin.
Blanco homered to right leading off the fifth, his second. But Cameron Maybin connected in the bottom half, hitting a drive to left-center for his second homer.
The Giants scored two runs in the sixth on second baseman Forsythe's two-base fielding error. With runners on second and third with two outs, Forsythe charged Blanco's grounder but it went under his glove. Joaquin Arias and Brandon Crawford hustled to home to give San Francisco a 6-3 advantage.
Olympic marathoner Meb Keflezighi of San Diego threw out the ceremonial first pitch. Keflezighi, who won the Rock 'n' Roll Half Marathon on Sunday, was the Olympic silver medalist in 2004 and won the U.S. Olympic trials earlier this year. ... The Padres will promote Jason Marquis on Thursday in time to start the series finale against the Giants. He was signed to a minor league deal on May 29. He was released by the Twins earlier in May. The Giants will counter with Matt Cain.