OAKLAND, Calif. -- Barry Zito never guessed the strike zone would be tougher to find than the visitors' clubhouse in his dreadful return to the Coliseum.
The Athletics hammered their former ace in his first start back in Oakland for the San Francisco Giants, tagging Zito for seven runs and six hits in a 15-3 victory to open the Bay Bridge Series on Friday night.
Zito also issued seven of the Giants' 13 walks in an awful night for the club and its $126 million left-hander, who couldn't get an out in the fifth inning. He won 102 games and the 2002 AL Cy Young Award during seven seasons with the A's, but never got comfortable on this trip to the mound he once owned -- perhaps because he had to approach it from the opposite side.
Zito (3-5) figured he had been in that visitors' clubhouse only twice during his seven seasons with the A's -- and he seemed appropriately lost throughout the night.
"It was kind of strange, (but) I don't know if my emotions played into it," said Zito, who claimed he didn't notice the mixed reaction of the Oakland fans. "It creeps into your mind that it's a different situation, but it's my job to block that out and treat them as normal opponents."
The A's were much better than normal against Zito, who matched his career high in walks before leaving his new club in a six-run hole at the stadium where he leads all active pitchers with 51 victories.
Dan Johnson hit a two-run homer and joined Eric Chavez in scoring three early runs apiece as Oakland snapped a two-game skid with a marvelous display of patience and timely hitting against Zito and his successors.
"Anytime you get a front-line pitcher, you try your best to make him work and get him out of the game as soon as possible," A's manager Bob Geren said. "That wasn't a special plan. It was a top-quality pitcher. You should always try and get him out of there."
A big loss got even uglier for the Giants in the eighth when reliever Steve Kline and manager Bruce Bochy were ejected moments after Mark Ellis hit his second career grand slam. Kline became furious with home-plate umpire Bill Miller over balls and strikes, and Barry Bonds repeatedly had to restrain the veteran left-hander.
"That's a game we have to wash off," Bochy said. "There's no getting around it -- we were awful tonight. ... You can't walk guys like we did and expect to win. The umpiring had nothing to do with tonight. We were bad."
Kline issued two walks, then didn't get a call on a 1-2 pitch before Ellis' grand slam. The Giants walked 13 batters for the fourth time since the franchise moved to San Francisco in 1958.
Chad Gaudin (3-1) soundly outpitched his big-money counterpart, yielding just two runs and seven hits over six innings. Even after Zito was chased, Travis Buck homered and Nick Swisher added a two-run double for the A's, while Johnson reached base five times.
"I didn't really think about it -- it was more a big deal for him coming back home," Gaudin said about his matchup with Zito. "I didn't play too much into it. I acted like it was just another game."
Bonds went 2-for-3 with two singles and a walk as the designated hitter in his ninth straight game without a homer for the Giants, who have lost seven of 10 to fall back below .500. Randy Winn extended his hitting streak to 17 games with a seventh-inning RBI double.
Zito's return turned sour right after he got leadoff hitter Shannon Stewart on a popup. The A's next six hitters reached base, including four walks and Bobby Crosby's bases-loaded infield single.
Zito walked home two runs in a 38-pitch first inning, escaping with only a three-run deficit thanks to Buck's double-play grounder.
Oakland added two more runs in the third on Chavez's leadoff single against his good buddy, followed by Johnson's fifth homer. Though his achievements have been slightly overshadowed by teammate Jack Cust's homer heroics, Johnson has five homers and 13 RBI already in an outstanding May.
The Giants pulled Zito after Chavez and Johnson again reached base to open the fifth, with A's fans directing sarcastic cheers at Zito as he jogged to the dugout.
"I expected them to back their team," Zito said. "They're great fans here, so if they didn't fully hate me, that's a good thing."
Cust then hit an RBI single on reliever Vinnie Chulk's first pitch, and Crosby's groundout scored Johnson on Chulk's second delivery.
- 2B Ray Durham (groin) and INF Rich Aurilia (neck) sat out for the Giants. Durham could return Sunday, while Aurilia should be available Saturday.
- A's RHP Rich Harden had another setback in his return from a strained right shoulder when the club shut him down for the weekend. Harden has been on the disabled list since April 16.
- Stewart left the game with a bruised left wrist after Chulk hit him with a pitch in the sixth inning, but he's expected to play Saturday.