Chien-Ming Wang got his first major league victory as New York overcame a two-run deficit and extended a regular-season winning streak to four for the first time since September.
"Our pitching staff has done a great job of getting us on this roll here," Martinez said. "Our confidence level obviously is growing."
Wang (1-1), a right-hander from Taiwan starting because Jaret Wright is on the disabled list, allowed runs in each of the first two innings but only two hits after that. He became the fifth straight Yankees starter to allow three runs or fewer, giving up three runs and four hits in 7 1/3 innings. The crowd of 39,780 gave him a standing ovation when he was taken out.
"He throws strikes," Yankees catcher John Flaherty said. "He worked fast. He challenges you to put the ball in play."
Before the game, Yankees manager Joe Torre and general manager Brian Cashman met with Giambi, whose average is down to .195 following an 0-for-15 slide. Giambi was asked whether he thought he would benefit from a minor league assignment, but he will remain with the Yankees for the road trip that starts Friday in Oakland.
As a veteran player, Giambi cannot be sent down without his consent.
Martinez, back with the Yankees for the first time since 2001, has taken over at first base in Giambi's absence and already has eight homers and 18 RBI. A fan favorite, he was given a curtain call after his homer in the five-run third put New York ahead 4-2.
Martinez, who agreed to a $3 million, one-year contract on Dec. 31, helped the Yankees win four World Series titles from 1996-00. No Yankee had homered in four straight games since Martinez did it from June 27 to July 1, 2001.
"I told him in the spring that numbers weren't important to me," Torre said. "He never stops demanding things of himself. He suffers so much when he doesn't feel he's earning his keep."
Aaron Sele (2-4) didn't make it out of the third inning, and the Mariners lost for the ninth time in 10 games.
"Not a ton of guys at my position have done it," Boone said. "But the way we're playing kind of supersedes it. It's no fun. The team's scuffling. It seems like everyone's having a hard time right now."
Sele dropped to 6-11 against the Yankees, giving up seven runs -- six earned -- and eight hits in 2 2-3 innings.
"Curveballs up, fastballs down for balls," he said.
Flaherty went 2-for-2 against Sele, improving to 8-for-16 with six RBI against the pitcher, whom he once caught in the minor leagues.
"His velocity was good. He just wasn't commanding any of his pitches, none," Mariners manager Mike Hargrove said. "When their guy missed, he missed down."
Flaherty hit an RBI single in the second, and Robinson Cano followed with a sacrifice fly.
Martinez, who doubled in the second, homered in the third for a 4-2 lead. Flaherty hit a run-scoring double and scored on a single by Cano, which stopped an 0-for-18 slide. New York got another run when Derek Jeter hit an infield single, Cano took a wide turn at second and third baseman Adrian Beltre threw the ball into the outfield for an error.
Given the lead, Wang breezed.
"I changed my release point," he said through a translator.
- Yankees RHP Felix Rodriguez tore cartilage in his left knee while getting out of a shower, Cashman said, and New York recommended he have surgery, which would probably sideline him four to six weeks. INF Russ Johnson will be brought up from the minors.
- Suzuki robbed Hideki Matsui of an extra-base hit with a lunging grab in right-center field in the third, and CF Jeremy Reed prevented a double by Alex Rodriguez, the next batter, with a diving catch in right-center.
- The Yankees are on their longest regular-season winning streak since taking five in a row from Sept. 5-9.
- Matsui went 0-for-5 and is homerless in 113 at-bats, a career high.