Sox second baseman Dustin Pedroia reaches first base on a misplayed ball in the third inning last night.

The Providence Journal / Bob Breidenbach

BOSTON — And now the magic number is zero, thanks to the Baltimore Orioles.

The Boston Red Sox are the American League East champions, for the first time since 1995.

With the Red Sox already having taken care of their own business at Fenway Park by beating the Minnesota Twins, 5-2, behind a strong performance by Daisuke Matsuzaka, knocking the magic number to one, they needed the Orioles to come from behind and beat the New York Yankees at Camden Yards.

Improbably, that’s what the Orioles did, rallying for a tie against the great Yankees closer, Mariano Rivera, on Jay Payton’s two-out, three-run double in the bottom of the ninth.

Melvin Mora’s surprise two-out, bases-loaded bunt produced the 10-9 Baltimore victory in the 10th, setting off a wild celebration at Fenway, where about 2,000 fans had remained in the stands behind the Boston dugout on the first-base line, watching the Yankees-Orioles game on the video screen.

The screen showed the first moments of the clubhouse celebration, where jubilant players doused each other with champagne and beer as they savored their accomplishment.

A short time later, the Red Sox, wearing new white T-shirts and hats emblazoned with the fact that they were the 2007 A.L. East champions, came out of their clubhouse and back onto the field to celebrate with their fans.

Alex Cora was first to pop his head out of the dugout, running along the top step of the dugout and spraying fans with champagne. Javier Lopez, Manny Delcarmen and Curt Schilling were next, and they went into the stands to do some spraying and sharing congratulations with the fans.

Even David Ortiz, wearing the championship T-shirt, made a triumphant appearance on the field, which was a bit of a surprise because only about a half-hour earlier, while several teammates were clustered on couches or chairs, watching the bottom of the ninth, Big Papi had been fully dressed and left the clubhouse.

But there he was, after doing a TV interview on the field that was broadcast to the fans, Ortiz had a bottle of champagne in his hand and hosed down a very willing Jonathan Papelbon as the ace closer, wearing swimming goggles to protect his eyes from the bubbly, stood along the first-base line.

The festivities capped a marvelous season for the Red Sox.

“This is an incredible satisfaction,” said Red Sox owner John Henry.

“This team played great baseball all year and deserved to be division champions,” added chairman Tom Werner. “They’re going to be dangerous in the playoffs.”

There still are two regular-season games to go this weekend against the Minnesota Twins, and the postseason awaits Boston, which was on manager Terry Francona’s mind after the crown had been claimed.

“There are still things to play for,” said Francona. “This was a very big accomplishment for this organization and for the city. We need this to just be the beginning, but it’s also a big accomplishment.”

“It’s game time,” said Schilling. “It’s October (when the postseason begins), and that’s when great players play great, and hopefully we have a couple of those guys in this clubhouse.”

“I’m proud of everybody,” said rookie second baseman Dustin Pedroia. “It’s an unbelievable accomplishment. It’s been a team effort all year and there are a lot of guys who have contributed. It’s been a great season and there’s plenty more to come. We’re not going to stop here.”

“I love this,” added Kevin Youkilis. “This is the best part of playing baseball. This is what you play baseball for. You put all the time and effort in and this is what it’s all about. But once this night is over we have to keep moving forward. We want three more celebrations because that’s when it gets really fun.”

Nevertheless, last night was a night to finally let all of the emotion of the long season wash over the Red Sox while they celebrated not only with each other but with the fans.

The Red Sox took over first place for good on April 18 when they beat Toronto, 4-1, on the road and never relinquished that lead. The Yankees made it a race over the final month of the season, but Boston had clinched a postseason berth on Sept. 22, and now the Sox have secured the division title.

Next up for the Red Sox will be the Los Angeles Angels of Anaheim in the Division Series, which will begin either Wednesday or Thursday at Fenway Park. Boston is tied with Cleveland for the best record in the American League, at 95-65. The team that finishes with the best record will have home-field advantage for the A.L. playoffs.

Last night, in events that soon took a back seat to the celebration, Boston jumped on top of the Twins early, pushing across two runs in the first inning. And they kept pecking away, adding a run in the third, another in the sixth and a solo homer by the red-hot Ortiz in the eighth.

Matsuzaka, meanwhile, looked as good as he has in a while in blanking the Twins until the seventh, when he surrendered a homer to Justin Morneau and an RBI groundout to Brian Buscher. He worked eight strong innings, finishing his first season in Boston with a 15-12 record, with Papelbon racking up his 37th save.

skrasner@projo.com