ST. PETERSBURG, Fla. — Now look who's one win away from the World Series.

The Boston Red Sox, playing like the defending champs they are, came out swinging and beat Tampa Bay 4-2 tonight to force a Game 7 in an AL championship series the Rays all but wrapped up two days earlier.

Slumping Jason Varitek hit a tiebreaking home run in the sixth inning as Boston evened the ALCS at 3-all. No late drama needed by the Red Sox this time — they rallied from seven runs down with only seven outs left to win Game 5.

Now Jon Lester starts Game 7 for the Red Sox on Sunday night against Matt Garza in a rematch of Game 3, won by the Rays 9-1 at Fenway Park. Last year, the Red Sox trailed Cleveland 3-1 before winning three in a row, then sweeping Colorado for their second Series title in four seasons.

"It's great to get to Game 7, to battle like this," said Kevin Youkilis, who homered and drove in two runs. "We went out there and played like it was our last game. It was awesome."

The pennant winner hosts the World Series opener Wednesday night against the well-rested Philadelphia Phillies, who won the NL pennant over the Los Angeles Dodgers in five games.

"It's all about how we react to the moment, and it's a seventh game," Rays manager Joe Maddon said. "It's a great learning experience. For us to win that game would be something special for us, also. So it's not about looking into the past. It's about looking into the future right now."

Red Sox ace Josh Beckett, who struggled in his first two starts of the playoffs, allowed two runs and four hits in five innings despite reduced velocity, and Hideki Okajima, Justin Masterson and Jonathan Papelbon combined for hitless relief.

"It's probably pretty appropriate. We come down to the last game, and whoever plays better gets to move on," Red Sox manager Terry Francona said.

B.J. Upton tied an AL record with his seventh home run of the postseason. After Boston went ahead 2-1, Tampa Bay tied it on Jason Bartlett's fifth-inning homer. But the Rays didn't get another hit, and the Red Sox improved to 9-0 in ALCS elimination games under manager Terry Francona.

Varitek, the Red Sox captain, had been 0-for-14 in the series before his homer in the sixth finished Shields, who allowed four runs and nine hits in 5 2-3 innings.

"He wears a 'C' on that jersey for a lot of different reasons, but none more important than how much respect everybody in that clubhouse, including players, coaches, upper management, has for him," Beckett said.

The Red Sox, trying to become the first repeat champions since the 1998-00 Yankees, were jubilant.

"We'll take runs any way we can get it," Francona said. "But the way it happened, and as hard as he's worked, it meant a lot to everybody. "

David Ortiz added an RBI single off J.P. Howell to pad the lead.

Boston bounced back from a 3-1 ALCS deficit in 1986 against the Angels, then in 2004 became the first major league team to win a postseason series when trailing 3-0, beating the Yankees for the pennant before sweeping St. Louis in the World Series. Then came last year's comeback.

It was a strange night in different ways. The first 20 minutes of the game weren't shown on television because TBS had an equipment failure.

And plate umpire Derryl Cousins left with a bruised collarbone after three innings, causing a 15-minute delay. Cousins was struck by a foul ball hit by Varitek in the second, but remained in the game until the delay. He was replaced by crew chief Tim McClelland, who had been working first base.

"The delay didn't really bug me that much. I had just come out," Beckett said. "I think James Shields probably had the worst end of that deal."

Upton, who only hit nine homers in 531 regular-season at-bats, homered in the first inning off Beckett, driving the ball off one of the catwalks at Tropicana Field. He tied Troy Glaus (2002) with his seventh homer in a single postseason, one behind record-holders Barry Bonds (2002) and Carlos Beltran (2004).

Right after that, the television broadcast began.

Youkilis led off the second inning with his drive into the left center-field seats off Shield, then gave the Red Sox a 2-1 lead in the third when he grounded out after Dustin Pedroia walked and raced to third on Ortiz's double down the right-field line.

Bartlett's homer tied it in the fifth.

Okajima pitched two scoreless innings, and Masterson got out of a potential tight situation in the eighth. He hit Bartlett with a pitch leading off and went to a 2-0 count on Akinori Iwamura when pitching coach John Farrell visited the mound. Papelbon struck out Iwamura, got two straight outs, and then Papelbon pitched a 1-2-3 ninth, extending his major league-record career postseason scoreless streak to 25 innings over 16 appearances.

"The important thing is we found a way to win this game," Varitek said. "It was a big win for us."