NEW YORK -- The Yankees have made it back where they believe they belong, heading into the postseason with a fluttering division flag to accompany their full head of steam.

With their 4-2 victory over the Red Sox on Sunday, the Yankees clinched the American League East for the 16th time in franchise history, then donned goggles before blasting bubbly around the spacious home clubhouse at Yankee Stadium to celebrate their first division title since 2006.

Finalizing their 100th win in front of a standing crowd of 47,576, the Yankees also whooped and hollered after having secured home-field advantage throughout the playoffs, gearing up for an AL Division Series for which an opponent has not yet been finalized.

The Yanks may not know who's coming to New York on Oct. 7 or 8, waiting for either the Tigers or Twins to win the tight AL Central race. But whomever it is, the Bombers know what they are, and that is reason enough to feel confident.

"I like our chances, but we've got to play well," captain Derek Jeter said. "All the teams that are going to the playoffs are good teams, and anything can happen in those short series. We've got to continue playing like we've been playing."

After taking five of six from the Angels and Red Sox, the Yankees feel as though they've already had some tuneup playoff games, testing themselves against the best the AL has to offer. The results are a nice boost to keep in their back pocket heading in.

"We're strong," Andy Pettitte, the winning pitcher on Sunday, said. "We've got a strong team and we know that, but this made it even more special, to beat Anaheim and win this series. We'll probably run into one of them in the postseason, but it's tough. It's a tough division and a tough league. Hopefully things will keep on rolling."

The ALDS matchup was out of the Yankees' minds as they whooped it up in the clubhouse of their billion-dollar ballpark, a clubhouse protected by large plastic sheets to guard against any errant bubbly seeping into the numerous flat-screen televisions and personal laptops installed in the lockers.

Manager Joe Girardi said before the game that he expected his players to be respectful of their home, but that didn't stop them from having fun, interrupting interviews and assaulting unsuspecting teammates with cold beverage baths.

"It's a great feeling for all of us," Nick Swisher said. "To be busting your tail since the middle of February -- coaching staff, training staff, strength staff, players, coaches, front office -- to get us where we are right now is a testament to everyone coming together as a group."

It was a season that began with some concern about Girardi's job security, as he sat behind his Spring Training desk and calmly confirmed the obvious -- if the Yankees didn't get back to the playoffs, someone else would be occupying his office in 2010. That no longer seems to be so pressing of an issue.

"Everybody in here has great respect for Girardi," Johnny Damon said. "Even when we were struggling, we were still going out there busting our [behinds] because we buy into Girardi's system. He's a great manager who didn't deserve the negativity that was coming his way.

"We have 100 wins, and hopefully there's 11 wins in the postseason we can get. This team is very special, and I like what we have here. I know this celebration is going to end soon. We understand there are bigger and better ones yet to come."

There are six games remaining on the regular-season schedule, and the Yankees can use them to rest their veterans and take a look at secondary players who might factor in to play a large role in the postseason. Girardi isn't sure if six games is the ideal amount of time for that, but it will certainly do.

"I don't know if there's an exact amount," Girardi said. "I've been on teams that have clinched it right away, I've been on Wild Card teams. The thing is, we've got a chance to rest some guys and play some other guys that could be role players during the playoffs."

Anticipating carrying 10 pitchers for the AL Division Series, the Yankees will start CC Sabathia in Game 1 and follow him with A.J. Burnett and Pettitte, though not necessarily in that order. Joba Chamberlain and Chad Gaudin could make the first-round roster as long relievers.

Beyond that, they have selections to make for their bullpen. Mariano Rivera, Phil Hughes and Phil Coke appear safe, but Brian Bruney -- who recorded five outs in Sunday's clincher -- is on the bubble. The Yankees are also waiting to see Dave Robertson in at least two games this week.

"We definitely have a young bullpen compared to the old ones that we had, guys with experience," Rivera said. "We have a young bunch of guys that have the hearts of a lion and want to do good."

Augmenting their veteran hub with newcomers, the Yankees clinched the 46th first-place finish in franchise history, the most of any professional sports franchise.

"You have to give those guys a lot of credit for the way they have welcomed in guys," Swisher said. "It's just been a great year. The core group of the Yankees, there's no denying the fact that these guys win."

And they have done it with a roster that genuinely seems to enjoy spending time together, which makes this team somewhat different from a few of its predecessors.

"I can't say enough about these 25 guys," Alex Rodriguez said. "I've never been around a group of guys that have been so close and love each other so much and respect each other so much."

The "Old Guard" of Jeter, Pettitte, Posada and Rivera knows what lies ahead in pursuit of the Yankees' 27th World Series title and first since 2000. For the rest, the adventure may just be beginning.

"We've still got some work to do, but this team is put together well," Sabathia said. "Who knows what can happen? We have a lot of fun on and off the field. It's a lot of fun when you can go out and play with guys that you really enjoy playing with."