ST. PETERSBURG -- The Red Sox try not to prioritize one game over another over the marathon of 162, but there was a different feel under the roof of Tropicana Field on Thursday night. This was a game and a series manager Terry Francona's team wanted to win badly, and it got both in grinding out a 6-3 conquest over the Rays in Thursday night's rubber match at Tropicana Field.

"We had to play good and we knew that coming in," said Francona. "It's nice to get out of here with a win tonight."

By doing so, the Sox extended their Wild Card lead over the idle Rangers to three and put the third-place Rays six games back. Considering that Tampa Bay, which still has a three-game series at Fenway from Sept. 11-13, would have been just four off the pace had it won, the importance was easy to see.

"A win is a win, but they're a little more magnified when it's head to head like that," said Red Sox left fielder Jason Bay. "You have a team that's chasing you for the Wild Card spot. There's still another team that's a little closer. But this game had a two-game swing in the standings. It's probably pretty important either way, for us and them. Lucky for us, we won it."

Clay Buchholz did his part to make that possible, offsetting a sluggish beginning and giving up six hits and three runs over six innings. It was Buchholz's fourth win of the season, and first against a team other than the Blue Jays.

"That was the first thing that went through my mind when [closer Jonathan Papelbon] got that last out," said Buchholz. "I finally got a win in the [United] States. We can go after whatever team I have next and try to just keep the train moving."

Offensively, the Red Sox did what they had to do. Mike Lowell's sacrifice fly in the sixth put Boston ahead for good.

Kevin Youkilis (two runs, three hits) and Jason Bay (two hits, two RBIs) also aided the cause. Rocco Baldelli, who spelled J.D. Drew in right, hit a towering solo shot against losing pitcher David Price.

Don't look now, but the Red Sox are settling into a late-season groove, as they head to Chicago with 12 wins in their past 16 games.

"I think it was a great series for us," said Baldelli. "It's not an easy place to play. Nobody likes coming in here. The Rays play really well in this building, but to be able to come in here at any point and win a series is very big."

It was the first time since 2007 that Boston won a series at the Trop, where it had lost 15 of its past 18 entering Thursday's rubber match.

"This is a tough place for us, a tough place for everybody," Francona said. "We've had a run here lately that hasn't been very much fun. I think part of that is that they're good and they play us very good, and for us to win here, you have to play good games. Five or six years ago, we'd come down here and Manny [Ramirez] or David [Ortiz] would hit a three-run homer and we'd get in their bullpen. I don't want to say have our way, but we'd win. Now you have to come down here and play clean baseball or you lose."

Of course, the most bitter memory the Red Sox have of Tropicana Field is their 2008 season ending amid a crushing defeat in Game 7 of the American League Championship Series.

Barring a miraculous turn of events in the standings, the Red Sox won't come to Tropicana Field again until 2010. And they might have signified the beginning of the end for the Rays by taking this series.

"Granted, it's definitely not over by any means," said Bay. "We do play them in another series. I like our spot right now. There's still a whole month of baseball left. Obviously you get close to the end, and each game is magnified. Better to be on top than looking up."

Trying to bounce back from Wednesday's loss, Boston jumped out first, thanks to a two-out rally which started with a double to left by Victor Martinez. Youkilis then banged one off the wall in left that looked like a double, but Martinez got a slow jump and held at second. That miscue became irrelevant when Bay ripped a double to left-center to bring home two runs, giving Buchholz a 2-0 cushion before he threw a pitch.

But Buchholz gave it right back in the bottom of the first. Ben Zobrist got the first run home with an RBI single. With two outs, Evan Longoria slammed an RBI double to right, tying it at 2. For Longoria, it was RBI No. 27 against the Red Sox this season. The last time an opponent drove in that many runs vs. Boston was 1960, when Baltimore rookie Ron Hansen had 28.

"It's not what you're thinking," said Buchholz. "You get two in the top of the first, you want to go out there and put up a zero. But that's a tough lineup. That's what they do is hit. They've done it all year to any team that comes into this place. They're good at what they do. I had to minimize that first inning. It could have been worse."

Baldelli's blast, his seventh of the season, put Boston back on top in the second.

The Rays tied it again in the bottom of the fourth. Longoria led off with a double and Gregg Zaun hit a well-placed grounder that took a big hop over Lowell and down the left-field line for an RBI double.

Buchholz got nasty after that, retiring the final nine batters he faced.

"I was maybe a little bit jittery in the first inning," said Buchholz. "It's it's a pretty big game. Everybody knows that we needed to win it to set the pace for the next month. After they got their first couple of hits, I told myself, 'Make pitches and you'll get outs.' I happened to get the last nine guys I faced, got them out. It doesn't always go like that, but when it does, it makes you feel good about the start."

The Red Sox stayed at it. With runners on second and third and one out in the sixth, Lowell did his job, hitting a sacrifice fly to center against reliever Russ Springer to score Youkilis with the go-ahead run.

Boston got two insurance runs in the seventh. The first of those runs was a chopper down the first-base line for an RBI single by Martinez, a hit that was reminiscent of the game-tying hit Zaun had earlier in the game.

"I don't know if that was the turning point in the game, but it sparked a couple runs in the inning," said Longoria. "If we get him to roll into a double play there, we get out of that inning and back into the dugout with some momentum. But some of the breaks went their way today."

However, breaks had nothing to do with the performance of the Boston bullpen. Billy Wagner, Daniel Bard and Papelbon (save No. 34) held Tampa Bay hitless over the final three innings.

"They were terrific, because the last thing we wanted to do was create situations," Francona said. "We've seen it before where they start running and balls are falling in and they can use that speed to their advantage. Bard was electric. I thought Wagner had to pitch a little bit. His velocity was down a little bit from what we've seen the last few times out. But he used his changeup and his breaking ball against some good hitters."

And the Red Sox, for the first time in recent memory, left Tropicana Field with a feeling of satisfaction rather than deflation.

"It was really good to get a win here tonight," said Youkilis. "Coming in here this time of year against a team that's in the Wild Card race with you, you've just got to come in and win the series, and we did a good job of that tonight. We just have to keep playing some good ball going into Chicago now."