Josh Donaldson backs Dan Straily as A's beat Giants

OAKLAND, Calif. -- The Oakland Athletics are back to following the formula that propelled them to the AL West title last season: a starting pitcher that goes deep into games, a little pop at the plate and a bullpen that protects the lead.

Josh Donaldson hit a two-run homer to back Dan Straily's strong start, and the A's beat the San Francisco Giants 4-1 in the Bay Bridge Series opener Monday for their fourth straight win.

"That started last year," A's manager Bob Melvin said. "It's just a little different feeling. You don't have to get up for these games. You don't have to find extra adrenaline."

Straily (3-2) allowed four hits and one walk in six innings. Buster Posey's groundout in the sixth drove in San Francisco's lone run.

Donaldson connected against Madison Bumgarner (4-3) in the fourth, and Yoenis Cespedes added a two-run double against George Kontos in the seventh to extend Oakland's lead.

Sean Doolittle pitched two perfect innings and Grant Balfour recorded his 11th save of the season for Oakland, which has won nine of 10 since falling to a season-low two games below .500.

"I didn't watch much of the playoffs last year, but I heard the Giants won the World Series," Doolitte said, sarcastically. "So they're the defending champs in your building. That's a crosstown rival. That's a game you get up for. Packed house. The crowd was electric. It was an awesome environment."

The usual sprinkling of green-and-gold clad fans mixed with San Francisco's orange-and-black following that traveled from across the bay to pack the Oakland Coliseum. The announced sellout crowd of 36,067 traded chants of "Let's go Oakland!" and "Let's go Giants!" throughout the cloudy afternoon.

Straily retired 14 of his first 15 batters and looked confident and in control from the start. Bumgarner struggled with his command -- matching a career high with five walks -- but didn't allow a hit until the fourth.

That hit turned out to be the difference.

Donaldson sent a cutting 89 mph fastball over the right-center field wall to give the A's a 2-0 lead. Donaldson raised his right hand in the air after jogging around first base, celebrating his eighth home run with a little extra flair.

"He had thrown a few balls in a row there and I guess wanted to challenge me right there and try to get a double play," Donaldson said. "But I was fortunate to put a good piece of wood on it and hit it out."

Bumgarner struck out six, was tagged for all four runs and also hit a batter in 6 2/3 innings. The lefty has lost three of his last four starts.

"I wasn't missing by a big margin," he said. "Had a lot of walks and that cost a couple runs. Tried to battle through. The biggest thing today was I wanted to try to go deep and give the bullpen a rest."

San Francisco squandered its best chance for a big inning when Posey grounded out in the sixth to score Gregor Blanco, snapping Straily's scoreless streak at 12 1/3 innings. Then Straily snared Hunter Pence's grounder to strand Marco Scutaro on third.

"Our offense has to get it going here a little bit," Giants manager Bruce Bochy said. "That's the kind of pitching we're going to need. It doesn't go down as a quality start, but he left the game with a really good start and that's what we're going to need playing these good clubs. He did all he could. Their guy pitched well."

Oakland's bullpen backed up his outing far better than San Francisco's did for Bumgarner, who was relieved after walking Chris Young with two outs in the seventh. Cespedes followed with a towering double off the right-center field wall that lifted Oakland to a 4-1 lead.

It was Straily's second straight scintillating start. He tossed seven innings of two-hit ball in a 1-0 win over Texas last week.

"I worked a lot quicker. Really, that's the pitcher I am," Straily said. "I was finally able to break through that and be myself -- work quick, fill up the strike zone. I've always said I'm a strike thrower and not a strikeout pitcher. That's what I truly believe."

Game notes
Giants reliever Santiago Casilla said he will have surgery Tuesday to remove a cyst from inside a bone in his right leg. He hopes to return just after the All-Star game on July 16. ... Oakland RF Josh Reddick, on the disabled list since May 8 with a sprained right wrist, began a rehab assignment Monday night at Class-A Stockton. He will shift to Triple-A Sacramento on Tuesday, where he will likely be at least three days, Melvin said. ... Giants CF Angel Pagan (sore left hamstring) sat out for the second straight day but hopes to be back in the lineup Tuesday. ... The Giants optioned RHP Sandy Rosario to Triple-A Fresno after the game to make room for lefty Michael Kickham, who will make his major league debut on Wednesday against Oakland's Jarrod Parker (2-6, 5.76 ERA). Kickham takes over the spot in the rotation vacated by Ryan Vogelsong, who fractured his right hand when he was hit by a pitch May 20.