BOSTON -- The American League Championship Series within his reach for the first time, Jason Bay got near his landing spot and then reached out his left hand as far as he could.

Once that hand swiped home plate late Monday night, Bay -- who scored the game-winning run on Jed Lowrie's walk-off hit to clinch Game 4 of the AL Division Series -- had reached his latest new destination.

"I could get used to this," glowed Bay during the champagne bath in the Red Sox's clubhouse.

Think about where Bay has gone over the past couple of months. On July 31, in a buzzer-beating deal, he was suddenly out of Pittsburgh, where he never tasted a pennant race, and in the middle of passion-packed Red Sox Nation. Oh yeah, he was merely part of a deal that included a future Hall of Famer named Manny Ramirez, who plays the same position (left field) and has the same job description (run producer).

It seemed like a whole lot of pressure. Yet Bay seemed to crave it, and he capitalized on it, helping to put the Red Sox in the postseason by hitting .293 with nine homers and 37 RBIs after the trade, to go with smart baserunning and solid defense.

But there was this whole playoff thing to encounter. Could Bay handle the pressure that October brings? The "experts" wanted to know.

So in Game 1 of the ALDS, Bay calmly belted a John Lackey fastball over the wall for a two-run homer in the sixth inning to reverse a 1-0 deficit and lead the Red Sox to victory. Game 2? All he did was belt a titanic three-run homer into the rocks in center field in the first inning, giving the Red Sox the fuel they would need for a 7-5 win.

Oh, then there was Game 3. The Red Sox lost in 12 innings, but Bay again came through, fielding a ball off the Green Monster from Torii Hunter and firing a perfect strike to second to nail Hunter.

And, yes, the capper. Bay helped put the finishing touches on the Angels with a one-out ground-rule double to right in the ninth inning of Game 4, and moments later, he scored that winning run.

This time around, you can be sure there will be little wonder if Bay can handle the moment.

"A lot of people asked me, 'Are you nervous?'" said Bay. "I'm just kind of using this time and this atmosphere to kind of embrace it and use it to my advantage, as far as really locking in and really sticking to your approach, rather than taking an at-bat or a pitch off in this atmosphere, and I think it helps."

Though Bay is the consummate professional -- it would be quite the challenge to find anyone in baseball who views him as anything less -- he can now admit that staying mentally strong in Pittsburgh for every moment of every season was hard.

"This is just a great atmosphere," Bay, 30, said of the postseason. "People try to explain to you what it's like or say, 'Have you ever imagined what it would be like?' Once you get out there, you really have no idea. I really enjoy it. It feels like every pitch is important. I think it's easy over the course of a season to take a pitch or an at-bat off -- there's so many. But you can't do that here. This gets you locked in."

For the Red Sox, Bay has been a force in the middle of the order, batting either fifth or sixth in manager Terry Francona's lineup. In the ALDS, the soft-spoken right-handed hitter produced to the tune of a .412 average (7-for-17), two homers, five RBIs, three runs scored and an .882 slugging percentage.

Befitting his humble nature, Bay always seems to be looking for teammates to give credit to rather than taking any credit for his own accomplishments.

"I think that, first of all, there's guys on every time I get up," said Bay. "We have so many big hitters in this lineup. Second of all, I think being in Pittsburgh and being in the middle of that lineup, and maybe the lack of options that we had, I was the guy. Teams were coming after me as such.

"In this lineup, I'm just another hitter. There's David Ortiz, there's Kevin Youkilis, there's Dustin Pedroia -- there's all these guys -- and I'm just another guy in the lineup. Maybe the anonymity kind of plays well in my favor."

Well, there's only one hole in that theory. When you play for the Red Sox -- and, for that matter, when you play in the postseason -- there's no such thing.

Bay and the Red Sox will play Game 1 of the ALCS against the Rays at Tropicana Field on Friday night.

One thing is for certain: Bay is looking forward to some more stomach-churning moments.

"Every pitch is life or death," said Bay. "It's a roller coaster, but that's why you play. It's a blast."

Sean Casey is the one player on the Red Sox who played with Bay when things were nothing like this. They were teammates on those Pittsburgh Pirates of '06.

"Playing with him in Pittsburgh in '06, I knew what kind of teammate he was, and I knew how awesome it was and I knew he was a diamond in the rough," Casey said. "Nobody knew about him, because he was in Pittsburgh. He would be a stud anywhere else. So coming over here, I was telling guys that he's a great teammate -- 'He's going to give you everything he has.'

"But other than that, he's a great player, man. He's a big home run hitter. He hits for average, drives in runs and does anything you tell him to do."

And the ego?

"His ego is on the negative scale," Casey said. "His ego is below the line that it should be."

Within about an hour of meeting Bay, Francona could pretty much tell that the newcomer would be just fine in his new environment.

"He knows these games are important," Francona said. "It's been a very welcome addition to our ballclub, though. [Bay is] very refreshing, very competitive, and I think he's enjoying this atmosphere a lot."

And now, Bay gets ready for yet another atmospheric change. With the ALCS comes yet another notch of intensity.

"It's been a blast every step of the way, and I'm looking forward to moving on," Bay said.