By Matthew Harrington

SAN FRANCISCO, Calif. – What a difference a bridge crossing can make. After commanding performances against the black and orange Monday and Tuesday night at O.Co Coliseum, the Oakland Athletics fell to the San Francisco Giants 5-2 at AT&T Park Wednesday night to open up Western half of the Bay Bridge Series. Matt Cain earned his second win of the season, going six strong innings of two-run ball while 2014 NL All-Star Hunter Pence collected two RBIs, including a solo home run to centerfield off recently acquired A’s starter Jason Hammel.

“Cain was how he normally is,” said A’s manager Bob Melvin. “It’s a mix of pitches. It was probably fifty percent fastballs, different pitches, backdoor curveballs and changeups.”

While Jeff Samardzija transitioned seamlessly into the A’s rotation in his debut following Friday’s deal with the Chicago Cubs, Hammel struggled in his first go-around with the green and gold. There were, however, moments where he showed promise, including wriggling out of a bases loaded, one-out jam with limited damage on one run in the third inning.

“That’s what you’re going to get out of me,” said Hammel. “I’m going to battle hard out there. Tonight was just a grind. They grinded me pretty good, but we still had a chance to win.”

Even with his tenacious mindset, the righty (0-1, 3.60 ERA) yielded three runs (two earned) against a Giants offense that’s been held scoreless in three of eight contests in the month of July entering play Wednesday night. The newcomer is the first Athletics starter to not go six innings and yield more than one run in a week.

The bar isn’t set as high for Hammel f as it does for the centerpiece of Billy Beane’s blockbuster, but there certainly is precedent for expectations from his spot in the rotation for the AL-leading A’s. After all, the 31-year-old’s arrival made southpaw Tommy Milone expendable, prompting a demotion to Triple-A Sacramento despite a 6-3 record and 3.55 ERA this season. Milone’s most recent start, a six inning, four-hit blanking of the then AL-East leading Blue Jays on Independence Day was fresh in A’s fans’ minds after Wednesday’s loss.

Behind Hammel, the AL West-leading A’s (57-34) found themselves playing catch-up early. San Francisco scored a run each in the second and third innings before Oakland could knick Giants starter Matt Cain (2-7, 4.18) for a run. The first two men to touch all four bases for the home team reached on a walk surrendered by the Oakland starter.

“I got myself into trouble with those deep counts and drove my pitch count up,” said Hammel. “They put together some pretty good at-bats. They were patient tonight. I didn’t help myself by walking guys.”

“I thought he threw the ball well,” said Melvin. “It looked like he got a little more comfortable as the game went along. He started mixing in all his pitches a little bit more. He’s got good stuff. It’s not exactly what he would hope for, but we didn’t do him any favors in the field or scoring runs.”

First basemen Stephen Vogt crushed a full-count fastball at the belt over the wall in right field and just shy of McCovey Cove for his third homer of the season moving the A’s within a run at 2-1.

Hammel couldn’t make the run hold up in the home half of the inning though, allowing a Hunter Pence homer on a low fastball to restore the two-run lead.

“It was a fastball down the middle,” responded Hammel when asked what he threw to Pence. “It was supposed to be a four-seamer in and it just cut a little over the plate and he got it.”

Hammel kept San Francisco (50-41) off the board in the fifth, but the frame was not without its drama. With Michael Morse on second base following a two-out double, Hammel delivered a ball to Gregor Blanco. After the delivery, the hurler clutched his catching hand in pain. After a lengthy visit from the training staff and a gruesome on-camera distortion of an extremity, Hammel finished off the inning, getting the Giants centerfielder to bounce into the inning ending force-out.

“In the middle of the pitch before, my hand just cramped up,” said Hammel. “I couldn’t get it to straighten out. I had to stop and figure out what was going on. It looked like I dislocated it, but it was just a really bad cramp. My thumb cramped up and went completely down. It was stuck for a little bit but it will be alright.”

After the game Hammel confirmed with the gathered media that he is, in fact, not disjointed. He also talked about his hope to continue on despite 99 pitches.

“I made a couple of good pitches to get the ground ball and get out of the inning,” said Hammel. “I wanted to go back out there but Melvin played it safe.”

With Hammel departed, Jed Lowrie swung momentum back in the A’s in the favor in the sixth inning after lacing a two-out single off Cain to plate Yoenis Cespedes. A rocky bottom half of the inning from reliever Eric O’Flaherty snubbed out any hopes of a shutdown frame. The lefty allowed two runs, including a single to Pence for his second RBI of the night and uncorked a wild pitch that brought home a run as well. A free agent signing in the off-season, O’Flaherty was activated from the disabled list earlier this month after missing most of 2014 following Tommy John surgery required after 19 appearances last season with the Atlanta Braves. He had allowed only one hit in his previous two innings of work in the current campaign.

The A’s will get back to work looking to clinch a victory in the 2014 incarnation of the Battle of the Bay series with a victory in an afternoon tilt at AT&T Park Thursday. If Oakland comes out on top, the A’s will take the rivalry series 3-1 after sweeping the first two games of the series in Oakland on Monday and Tuesday.

“These games mean a lot in this area,” said Hammel. “This is as close to a playoff atmosphere as you can get right now.”

History isn’t on Minnesota-bound A’s lefty Scott Kazmir’s side when the All-star goes against former Athletic Tim Hudson under the San Francisco Sun Thursday. The A’s have lost 13 of the last 15 games at the ballpark on the shores of McCovey Cove.

“We were 1-1 last year,” said Melvin. “That’s all I remember. When you have two teams that play competitive ball against each other, home field will come into play. We have a good road record this year, but I’m sure they got a boost from their crowd tonight as well.”