San Francisco Giants starting pitcher Madison Bumgarner works against the Atlanta Braves in the fifth inning of a baseball game on Friday, June 14, 2013 in Atlanta.

ATLANTA - Back-to-back shutout wins have reminded the Giants they expected to lean on strong starting pitching to defend their World Series championship.

That hasn't always been the case and Madison Bumgarner said it's a good time for the staff to get more consistent.

Bumgarner allowed two hits in seven innings and combined with Sandy Rosario for a three-hit shutout in the San Francisco Giants' 6-0 victory over the Atlanta Braves on Friday night.

The win came one day after Matt Cain was similarly dominant in leading San Francisco to a 10-0 shutout of the Pirates.

The consecutive shutouts are highlights in an overall slow start for the staff. Bumgarner (6-4) and Cain (5-3) each moved two games over .500 with the latest wins. Tim Lincecum is only 4-6 and Barry Zito is 4-5.

"We're all just not catching any breaks right now," Bumgarner said. "We've all got to start locking it in. We're coming up on the second half here. If we want to make a playoff push, I think everybody knows it's time to turn it around."

Bumgarner was dominant in earning his second straight win. The left-hander did not allow a baserunner for 4 2-3 innings before losing his bid for a perfect game in the fifth and shot at a no-hitter in the sixth.

Bumgarner matched his season high with 10 strikeouts while walking one.

"He really has been consistent all year, but this was up there as one of his best starts," Giants manager Bruce Bochy said.

Atlanta's Kris Medlen (3-7) lasted six innings and gave up four runs on nine hits, including a homer by Gregor Blanco to lead off the game. The Giants had five doubles off Medlen.

Bumgarner said he never thought Blanco's leadoff homer would provide the only run he would need, especially after he didn't feel sharp when warming up before the game.

"No, not against a team like this," Bumgarner said. "It wasn't terrible in the bullpen, but it wasn't very good and so I kind of needed to get it together. Fortunately, I was able to do that and dial it in and make pitches and it worked out in our favor."

Buster Posey had three doubles. Blanco had two hits, including a run-scoring single in the second.

Rosario allowed one hit in two scoreless innings. Andrelton Simmons singled with one out in the ninth and moved to second base on Jason Heyward's groundout. Rosario struck out Justin Upton to end the game.

The Braves, who were swept in a three-game series at San Diego to end a 2-5 road trip, have lost four straight.

Atlanta couldn't push a baserunner past second.

"Right from the very beginning we go down 1-0 and they added some runs, which probably made (Bumgarner) even tougher to face," Braves manager Fredi Gonzalez said.

"Our bats didn't look very good, I think, because of that. We couldn't put the ball in play."

Bumgarner, pitching one year and one day after Cain's perfect game against Houston, did not allow a baserunner until B.J. Upton walked with two outs in the fifth. Bumgarner then struck out Dan Uggla, who remained at home plate to argue the called third strike with umpire Gary Darling.

Atlanta's Brian McCann also disagreed with a called third strike by Darling earlier in the fifth inning.

Chris Johnson led off the sixth with a bloop single to right-center field for Atlanta's first hit.

Bumgarner had a quick answer when asked when he became aware he was working on a no-hitter.

"After the first out," he said.

The Giants took a 2-0 lead in the second when Joaquin Arias doubled and scored on Blanco's single. The Giants added a run in the third on back-to-back doubles by Posey and Hunter Pence. Two more doubles by Posey and Brandon Crawford in the fifth pushed the lead to 4-0.

San Francisco added two runs off Braves rookie Alex Wood in the seventh. Posey's third double drove in Tony Abreu, who walked. Wood, who walked two more batters in the inning, forced in a run with his bases-loaded balk with Andres Torres at the plate.

Braves general manager Frank Wren announced during the game that right-hander Brandon Beachy will not make his scheduled 2013 debut in Tuesday's doubleheader against the Mets.

Wren said Beachy, returning from elbow ligament-replacement surgery in June of last year, was "a little tender" following Thursday night's rehab start for Triple-A Gwinnett in Rochester. Beachy was back in Atlanta on Friday and was examined by a Braves doctor.

"We think it's a very minor setback," Wren said.

"We're not sure exactly when we'll insert him back in. It's really a function of when he's feeling good again."

NOTES: Blanco's homer was his first of the season and his first career leadoff shot. ... Wren said the Braves would select a replacement starter for Beachy on Sunday. ... Giants 2B Marco Scutaro, hit by a pitch on his left pinkie finger on Tuesday, played some catch before the game and hit in the cage. Bochy said Scutaro is "coming around" but is in a "holding pattern" until the team returns to San Francisco on Monday. ... Bochy said OF Angel Pagan (hamstring) is "not quite ready" to come off the 15-day DL but is improving. ... Braves LHP Mike Minor will face Giants RHP Chad Gaudin on Saturday.