SEATTLE -- Frank Thomas showed how healthy he is.
Thomas hit a three-run homer into the second deck and scored from second base on Nick Swisher's RBI single to lead the Oakland Athletics over Seattle 7-6 Sunday for their 12th consecutive win against the Mariners.
The A's, who have won seven of eight, swept a three-game series in Seattle for the first time since Sept. 24-26, 1993. Thomas was 7-for-13 with a homer and six RBI in the series, including three hits on Sunday.
"I'm healthy again," said Thomas, who was hobbled last year by ankle problems. "I had a major injury and I'm ready to go back to where I am, one of the top players in the game. I know what I've been able to bring to the table day in and day out when I'm healthy."
Oakland, which went 5-1 on a trip against the Los Angeles Angels and the Mariners, returned to the Coliseum for a nine-game homestand with a season-high three-game lead in the AL West.
Thomas homered with an 0-2 count and two outs in the third against Gil Meche (9-6), connecting on a 95 mph fastball for his 24th homer. Meche said he was just trying to throw a waste pitch, but instead watched Thomas move past Tris Speaker and Jeff Bagwell into 40th place on the career RBI list with a 404-foot shot.
"He threw two incredible curveballs before that," Thomas said. "I was just going to sit back and hit it hard. Fortunately, I got a high fastball that I can handle."
Thomas added a run-scoring single in the fifth to raise his RBI total to 1,532, five behind Joe DiMaggio, who is 39th. He was running when Swisher singled to right on a 3-2 pitch.
"I was lucky to get a head start," Thomas said. "That was important, and I wanted to score for Swish."
Swisher hit his 23rd homer in the eighth inning off Sean Green. He was 2-for-14 entering Sunday and hit his first homer since July 26 against Boston.
"We're playing extremely good baseball," Swisher said, "but you don't want to get yourself on that emotional roller coaster right now."
Joe Blanton (12-9) improved to 4-0 against Seattle this season, allowing three runs and 10 hits in six innings. Oakland's bullpen preserved the win for Blanton, but it wasn't easy as Seattle rallied from a 6-2 deficit.
Huston Street replaced Justin Duchscherer with a 7-4 lead and the bases loaded with one out in the eighth. Adrian Beltre blooped an RBI single just in front of charging left fielder Bobby Kielty, and Raul Ibanez then grounded to first on the next pitch.
Swisher threw down to second, but shortstop Marco Scutaro couldn't make a relay throw after being taken out on a hard slide by Beltre, and Willie Bloomquist scored. Richie Sexson took a 3-2 slider for a called third strike, ending the inning.
Yuniesky Betancourt blooped a single that second baseman Mark Ellis lost in the sun with two outs in the ninth and stole second before Street struck out Bloomquist for his 25h save.
"Losing, it's no fun," Bloomquist said. "We had opportunities, had our chances. Me personally I had a chance to tie the game up there. I don't like fanning and I'm not real happy about it."
Meche, the only Seattle pitcher to beat Oakland this season, allowed six runs -- four earned -- and eight hits in five innings. He is 0-2 in four starts since July 14.
Ibanez and Sexson hit two-out RBI singles in the first, but Sexson was thrown out at the plate by Milton Bradley trying to score on Kenji Johjima's single to right.
Thomas' homer and Jay Payton's RBI double gave Oakland a 4-2 lead in the third, and RBI singles by Thomas and Swisher extended the lead in the fifth.
Sexson hit an RBI double in the bottom half, and pinch-hitter Eduardo Perez singled in a run off Duchscherer in the seventh.
Seattle and Oakland play six more times, including a three-game series in Oakland starting Aug. 14.
"Obviously we know we are 6½ games out, but we don't feel like we're out of this thing," Seattle manager Mike Hargrove said.
- Thomas has 472 homers, three behind Willie Stargell and Stan Musial, who are tied for 23rd place.
- The 12 wins in a row against one team is the second-longest streak in Oakland history, trailing a 16-game win streak against the New York Yankees from September 1989 to May 1991.
- Seattle's longest losing streak vs. one team is 15 against the Boston Red Sox from May 1977 to June 1978.
- CF Mark Kotsay extended his hitting streak to 13 games with a single in the third but left in the seventh following back spasms.