NEW YORK - Even Kevin Millwood was caught up in Andy Pettitte's return to the big leagues.

Still, he was happy to play the spoiler.

Millwood pitched three-hit ball for seven innings and Casper Wells and Justin Smoak each hit a two-run homer, lifting the Seattle Mariners past Pettitte and the New York Yankees 6-2 Sunday to avoid a three-game sweep.

"I was watching him," Millwood said of Pettitte, who hadn't pitched since retiring after the 2010 season. "I think everybody was kind of curious."

Millwood (1-4) almost missed out on the 2011 season, too, but not by choice. He spent much of the year in the minors with the Yankees and Red Sox before joining the Colorado Rockies' rotation in August. He signed with Seattle in the offseason.

He was winless in six starts this year, but the 37-year-old right-hander kept the Yankees guessing Sunday. He got his 2,000th career strikeout and was helped by three double plays.

"I felt like I changed speeds pretty well, moved the ball around," Millwood said.

Mariners manager Eric Wedge was impressed with Millwood's pitch selection.

"I thought he was outstanding today," Wedge said. "He did a great job with his secondary stuff, working off his fastball."

The Yankees tried to prevent their old pal Pettitte from taking the loss with a rally in the eighth against four Seattle relievers. Robinson Cano was walked with two outs by Charlie Furbush with the bases loaded to make it 4-2. Mark Teixeira, though, struck out to end the inning.

The lovefest for Pettitte (0-1) began when the lefty appeared with several players in videos welcoming fans to Yankee Stadium after batting practice. The cheers grew as he strolled out to the bullpen for warmups and fans rose for a standing ovation when the five-time World Series champion followed his teammates onto the field for the first inning.

Yankee Stadium got awful quiet, though, when Wells homered in the sixth to give Seattle a 4-1 lead with his first of the season, an opposite-field drive off the netting on the right-field pole. Smoak homered for Seattle's first hit with two outs in the fourth.

A big Yankees fan growing up, Wells thought facing Pettitte, his sister's favorite pitcher, made the day even more special.

"Facing Andy Pettitte, it's a lot of things coming true, so it's pretty special," said Wells, who grew up in Schenectady, N.Y.

Pettitte's return had become more important to the Yankees because their rotation had been struggling, with Freddy Garcia demoted to the bullpen. But through the first five games of this homestand, the team's starters were 4-0 with a 1.31 ERA and manager Joe Girardi thought their performance would take some of the pressure off Pettitte.

The broad-chested 39-year-old appeared calm as ever in his first big league start since Game 3 of the AL championship series against Texas on Oct. 18, 2010. He sat out last season before deciding in mid-March to make a comeback.

With his cap pulled low, and peering over his glove held up in front of his nose, it looked as if No. 46 never missed a game for New York.

After Nick Swisher caught leadoff batter Dustin Ackley's fly to right with a leap at the wall, Pettitte walked Wells. He then got Ichiro Suzuki to ground into a double play. Pettitte walked Alex Liddi with two outs in the second but Mike Carp grounded out to end the inning.

"I just cannot believe how comfortable this is for me," Pettitte said. "I don't know how to explain it."

Not having allowed a hit two outs into the fourth, Pettitte walked former Yankees prospect Jesus Montero and Smoak lined a homer to left. Pettitte showed little emotion on the mound.

Wells homered following Ackley's leadoff single in the sixth. The Mariners then loaded the bases with one out on three straight singles but Girardi stuck with Pettitte, and Carp grounded to first. Teixeira stepped on the bag and threw home, and catcher Russell Martin tagged a sliding Montero.

Montero, wearing pink shoes for Mother's Day, limped off the field.

Pettitte returned for one batter in the seventh and induced his 12th groundball out. He left to a loud ovation despite trailing 4-1.

Millwood had little trouble in his best start of the season. With runners on first and second in the third, he got Derek Jeter to ground into the first of his two double plays.

Jeter also hit into an inning-ending double play after Millwood walked Martin to force in a run in the fifth. Alex Rodriguez grounded sharply into a 6-4-3 double play after a leadoff walk to Curtis Granderson, one of four walks by Millwood.

"We turned some big double plays," Millwood said.

Millwood fanned Granderson leading off the fourth for his 2,000th career strikeout.

NOTES: The Mariners had lost eight in a row on the road. ... Jeter's single in the eighth was hit No. 3,142, tying him for 16th place on the career list with Robin Yount. ... Pettitte came in 11-11 against Seattle. The only other AL team that he doesn't have a winning record against is Cleveland (8-8). ... Wells' homer was the Mariners' first hit with runners in scoring position this series. The were 0 for 10 coming in.