Bowker hit a go-ahead, three-run homer in the eighth inning to spoil Fernando Rodney's season debut, and the Giants won their first interleague game in seven tries this year with an 8-6 victory over the Detroit Tigers on Monday night that ended a five-game skid at home.
"Any time you come from behind, those are great wins," said manager Bruce Bochy, who watched on TV from a side room between the dugout and clubhouse after being ejected. "We've had a hard time getting the big hit at home. ... Bowker, he came through tonight. That was huge."
Marcus Thames homered twice and drove in three runs for the Tigers, who had their season-best six-game winning streak snapped. Thames has connected in four consecutive games.
Bowker fell behind 0-2 then hit a 1-2 changeup into the seats in the right-field arcade, the first batter faced by Rodney after he relieved Freddy Dolsi (0-2) with two runners aboard. The Tigers activated Rodney from the disabled list earlier in the day after the setup man had missed the entire season with shoulder problems.
"I knew I hit it good but I didn't know if it would go over," Bowker said. "It was pretty cool."
Keiichi Yabu (3-3) pitched the eighth for the win. Fred Lewis homered and added a two-run double in the big eighth inning. Giants closer Brian Wilson got into a bases-loaded jam in the ninth in a non-save situation and allowed Curtis Granderson's two-run single.
Ivan Rodriguez tripled to lead off the seventh and put the Tigers ahead on a disputed play at the plate on pinch-hitter Edgar Renteria's sacrifice fly, but Detroit couldn't hold on for starter Justin Verlander.
Bochy was thrown out for arguing the play at the plate.
"It was a big play and obviously we disagreed on it," Bochy said.
Right fielder Randy Winn caught Renteria's liner and fired the ball home. Replays appeared to show that catcher Bengie Molina tagged Rodriguez with his glove at the start of his slide. Bochy hurried out to argue with plate umpire Tom Hallion, who didn't wait long to toss the skipper -- his third ejection this year.
"I tagged him on the back -- I felt that," Molina said. "That's a tough position for the umpire. He was not in good position."
Thames had his sixth multihomer game and second this year, the other coming on May 28 at the Los Angeles Angels. The homers were just the fourth and fifth allowed by Giants starter Tim Lincecum this season.
Thames made it a career-best four straight games with a homer when he connected for a two-out solo shot in the second that was the first hit of the night off Lincecum. Thames hit a two-run homer in the fourth for his 12th of 2008, giving him homers on his last seven hits.
"I'm just trying not to miss my pitches," Thames said. "He's got really good stuff and you can't miss the pitches he hangs. When I saw it hanging I smiled and tried to hit it hard. Both starters threw a great game. To be honest, I didn't think it would be that high scoring."
Lincecum hadn't allowed a home run in six starts and 42 2/3 innings since the Phillies hit two off him on May 10.
"Those were pretty big mistakes in that game, as close as it was," Lincecum said. "Both those were probably letter high and begging to get hit."
San Francisco bounced back from a weekend sweep at home by the Oakland Athletics for just its fourth win in 15 at home.
Lewis hit a tying home run leading off the fifth against Verlander, who struck out seven and walked one in six impressive innings. He allowed three runs and five hits as the Tigers lost for only the 10th time in 43 games against NL teams since the start of the 2006 season.
Tigers manager Jim Leyland was happy to see Rodney back on the mound.
"He threw the ball good. It was bad location. We were going for the strikeout there and we almost got it," Leyland said. "We played a good game and we had good at-bats. Our bullpen just couldn't hold it. That's all. We made bad pitches in big situations."
Lincecum, who has won four straight decisions, escaped his first loss since April 29 against Colorado. He allowed more than three earned runs for the first time in 20 starts since Aug. 11 last year against Pittsburgh.
Molina ended an 0-for-17 stretch with his sixth-inning single. ... Detroit OF Gary Sheffield, sidelined since May 27 with a strained muscle in his left side, was set to start a rehab assignment for Class-A Lakeland.