The Sox’ Kevin Youkilis is tagged out trying to get back to first base in the first inning after attempting to stretch his RBI single.

The Providence Journal / Kris Craig

BOSTON — Jon Lester is getting stronger every time he takes the mound, and now he’s pitching like it’s the end of October.

Once again the left-hander propelled the Red Sox to victory last night, pitching 7 2/3 scoreless innings in which he allowed only six hits, walked three and struck out nine as Boston beat Tampa, 3-0, and cut its deficit to just a half-game behind the division-leading Rays.

Because Lester has been such an effective part of the Sox’ rotation, manager Terry Francona and his players have come to expect this type of outing from the southpaw.

“I can’t remember going into a game (Lester was pitching) where we felt like we weren’t going to win,” said Francona. “He certainly has been solid.”

It wasn’t too long ago when the Red Sox had the shackles tightly secured to Lester’s left arm. The organization was very careful with his pitch counts.

Now it’s Lester’s game.

Physically he’s stronger. Mentally he’s stronger. His maturity is exactly where it needs to be, especially with the postseason in clear view. His work ethic has always been there and as a result Francona has more trust in his left-handed ace.

Case in point: Last night was the 17th time this season he has thrown over 100 pitches in a game. The most he threw were 130 on May 19 against Kansas City, and last night he tossed 118. The Red Sox have only lost once in those 17 outings.

“It’s been good,” said Lester, referring to the manager’s confidence in him. “It’s been fun for me to have that trust from my manager and the team. Just because I’m at 105 pitches doesn’t mean I’m done with the game. They trust that I’m going to be around the zone and hopefully get a couple of guys out.”

Lester has now shut out his opponent seven times this season, having lasted at least 6 2/3 innings in each game. He improved to 9-1 at Fenway Park with a 2.66 ERA and he remains unbeaten in seven career starts against the Rays. This season he’s 3-0 with a 0.90 ERA when he’s faced Tampa.

So, what is it about pitching at Fenway Park?

“It’s home,” Lester said. “When you’re at home you sleep in your own bed and you have your own routine. You don’t have to worry about room service. You don’t have to worry about taking a cab to the field. You have a comfort level and you can do things during the day that keep your mind occupied. It’s easy to pitch here. Your routine stays stable.”

Lester said he’s more consistent with his mechanics and is not wasting energy. He’s been more efficient because of that, and it shows.

The Red Sox gave him a 3-0 cushion in the bottom of the first inning and that was all he would need as David Ortiz, Kevin Youkilis and Jason Bay provided the RBI. Bay crushed a solo homer for his 28th round-tripper of the season, his sixth since arriving in Boston.

Bay wasn’t talking about his offensive heroics after the victory, however, he was praising his starting pitcher, who he didn’t know too much about before he became a Red Sox.

“Not a clue,” said Bay. “He’s absolutely filthy and I’ve seen it first-hand. He’s been absolutely dominating.”

Lester never been one to bother with peripheral distractions. He knew what was at stake last night.

“It was important,” said Lester. “It was more important than a normal start. Obviously they are ahead of us right now, and we’re trying to get back in first place. It was a good atmosphere in the ballpark tonight. It almost felt like we were in the playoffs. We’re playing good baseball right now and we’re swinging the bats well and playing good defense. Hopefully we can keep going forward and keep this thing going.”

Boston has trailed Tampa in the A.L. East standings since the All-Star break, and with this three-game set at home, and another at Tampa next week, the Red Sox are hoping to come out on top.

After Lester’s outstanding performance, Red Sox closer Jonathan Papelbon entered the game in the top of the eighth inning with two outs and two on and Cumberland’s Rocco Baldelli at the plate. Papelbon struck out the Rays’ DH on a 97 MPH fastball. Baldelli went 0-for-4 with four strikeouts.

“Obviously when you bring Pap in it’s a good situation,” said Lester. “You have the best closer in baseball, so bring him in.”

Papelbon retired the side in the top of the ninth to record his 36th save of the season.

Prior to last night’s game, many Tampa players and team personnel spoke about how different it is to be playing meaningful games at Fenway in September.

“There’s a positive attitude,” said Rays pitcher and Warwick native Dan Wheeler. “We’re extremely happy to be here. We’re hopefully on the verge of a playoff spot. It’s a lot of fun to be playing some meaningful games in September. There’s nothing like it. It’s a different guy every day who steps up. You can’t stay enough about our starting pitching and our defense.”

“They’re exciting,” said Francona. “It’s exciting to get into a situation where the games are so meaningful. They’ve turned themselves into a bonafied contender. What they’ve done for baseball is exciting, but it’s made our job a little tougher. It makes these games more exciting.”

jmcdonal@projo.com