Oakland, CA (Sports Network) - Josh Donaldson hit a two-run home run to back six strong innings from Dan Straily as the Oakland A's took the first of a two-game set with the San Francisco Giants, 4-1, on Memorial Day.
Straily (3-2) scattered just four hits and a run while tossing 52 of his 78 pitches for strikes. Sean Doolittle faced the minimum in two innings of relief before Grant Balfour shut the door for his 11th save of the season in as many tries.
Yoenis Cespedes hit a two-run double for the A's, who have won four straight and nine of 10.
Madison Bumgarner (4-3) took the loss after yielding all four runs on four hits while striking out six. He also matched a season-worst with five walks in 6 2/3 innings.
Bumgarner walked Cespedes on four pitches to open the fourth inning and fell behind Donaldson 2-0 when the A's third basemen unleashed his eighth homer of the year, which narrowly cleared the wall in right-center field. The home run was the first hit Bumgarner allowed.
Jed Lowrie and Nate Freiman followed with singles, but Bumgarner struck out the side to avoid further damage.
Buster Posey brought the Giants back to within a run with his RBI groundout to shortstop that plated Gregor Blanco with one away in the sixth.
Oakland added to its lead with two runs in the seventh on Cespedes' two-run double off the wall in right. Derek Norris and Chris Young, who had reached on a single and walk, respectively, came around to score.
Posey drew a one-out walk in the ninth, but Balfour got Hunter Pence to ground out and Brandon Belt to look at strike three to end the tilt.
GAME NOTES: San Francisco has lost six of its last 10 ... Balfour has converted 29 straight save opportunities, which is second best in A's history ... Posey went 0-for-3 and his 10-game hitting streak came to an end ... The Giants were 0-for-7 with runners in scoring position.