CLEVELAND -- Barry Zito finally placed as much faith in himself as the San Francisco Giants did when they signed him.
Signed to a $126 million, seven-year contract before last season, Zito (3-11) got his first interleague win for the Giants on Wednesday with a 4-1 victory over the Cleveland Indians.
"That's the Zito we know," Giants manager Bruce Bochy said. "He had great rhythm, pounded the strike zone and threw all his pitches very well."
Cleveland lost for the sixth time in eight games. Combined with Kansas City's 4-2 win over Colorado, the Indians fell into last place this late in a season for the first time since the AL Central was formed in 1994.
Cleveland had not been last this late since it was in seventh place in the AL East on June 25, 1993.
Zito allowed one run and four hits in 6 2/3 innings, striking out four without a walk in his best start of the year. He bounced back from one of the shortest outings of his career last Wednesday when he lasted only two innings in a 7-2 loss to Detroit.
"I was just letting it fly and trusting myself, which is the hardest thing to do in baseball," Zito said. "I definitely feel like I'm back."
The left-hander came in 0-6 with a 9.32 ERA in interleague play since signing with the Giants before the 2007 season. He had gone 0-8 since his previous interleague win, June 16, 2006, against the Los Angeles Dodgers when he was with Oakland.
"I looked at my record and stats and figured things couldn't get any worse," Zito said. "So then why not just go out, trust my stuff and don't worry?"
Jose Castillo had three hits, including a homer, for the Giants, who improved to 4-10 in interleague action, the same record Cleveland has against NL clubs this season.
Zito said striking out All-Star Grady Sizemore on three pitches to open the first inning boosted his confidence.
"I threw fastball, curve, slider to probably the best leadoff hitter in the game," Zito said. "I felt good in the bullpen warming up and it carried over."
Zito said he still felt strong in the seventh, when he yielded a two-out double to Kelly Shoppach and was lifted. He pounded his glove in disgust as he left the mound.
"I felt like he had reached that point," Bochy said. "He threw great. It was time for us to pick him up."
Zito said he understood Bochy's decision, but after months of struggling, wanted to keep going.
"I'm competitive and wanted to stay out there," Zito said. "I wanted to make sure they didn't think I was tired."
Pinch-hitter Shin-Soo Choo greeted reliever Keiichi Yabu with a single, scoring Shoppach to bring the Indians to 3-1.
John Bowker hit his eighth homer in the eighth off Rafael Betancourt to make it 4-1.
Brian Wilson pitched the ninth for his NL-leading 21st save in 23 chances and 12th in a row.
Aaron Rowand put the Giants ahead 2-0 with a two-run single off left-hander Jeremy Sowers (0-3) in the first inning. Castillo and Randy Winn both singled with one out and Bengie Molina walked to load the bases.
Rowand, hitting .380 against lefties, lined a 2-2 pitch to left-center, scoring Castillo and Winn. Sowers got out of further trouble by getting Rich Aurilia to hit into a double play.
Castillo hit his sixth homer with one out in the third to make it 3-0.
Zito improved to 6-3 in his career against the Indians, facing them for the first time since a 7-6 win on May 6, 2006, when he was with the Athletics.
"We were totally ineffective against him for some reason," said Indians second baseman Jamey Carroll, who had two singles off Zito. "Even after a couple of times through the order, we took the same approach. He had more life on his fastball than we saw on video."
Sowers gave up three runs, nine hits and five walks over seven innings, striking out three.
Cleveland's Casey Blake started at third base, but moved to shortstop for the first time in his career in the eighth inning. ... Castillo has hit .538 (7-for-13) in his last three games. ... OF Fred Lewis, who has played in 76 of the Giants' 77 games, wasn't in the lineup. He had a career-best 12-game hitting streak snapped Tuesday. Lewis batted .391 (18-for-46) during the streak. 2B Ray Durham batted in Lewis' usual leadoff spot. ... Giants SS Omar Vizquel got a seventh-inning single, snapping an 0-for-23 skid. ... The Indians have never beaten the Giants in Cleveland. They are 0-2 in this series and were 0-2 in losing the 1954 World Series in four straight. ... The crowd of 25,654 pushed Cleveland's home attendance past 1 million for the season.