Daisuke Matsuzaka allowed two runs and had eight strikeouts in six innings yesterday.

BOSTON — Three games may not necessarily make a season, but the last few for the Boston Red Sox have been crucial.

With yesterday’s 5-2 victory over the Oakland Athletics at Fenway Park, the Red Sox completed a three-game sweep and will now play the next seven games on the road against Kansas City and Chicago. Boston is hoping these last three games will set the tone for the rest of the season now that the trade deadline has passed.

“One of the things that we talked about was not looking back or looking forward,” said Red Sox manager Terry Francona. “We’re just kind of attacking what’s at hand and we did that very well. We played with energy and it was a good day.”

The tension (aka Manny Ramirez) has been removed from the clubhouse. The club now knows exactly what it has moving forward. It has set its goal to defend its World Series championship and the last couple of days have helped the Sox move in the right direction.

“I’ve only been here for a month in April and for a couple of weeks before the trade deadline, and when you’re that new to a team you can feel the tension,” said rookie shortstop Jed Lowrie, who has been a major contributor of late. “That just says that a lot of these other guys had to be feeling it a lot more than I did.”

Red Sox starter Daisuke Matsuzaka improved to 12-2 with a solid six-inning performance in which he allowed only two runs on four hits with two walks and eight strikeouts. Timely hitting was also key for Boston yesterday as Kevin Youkilis provided an RBI single, Lowrie added a two-run triple and Coco Crisp contributed a pair of sacrifice flies en route to victory.

“It’s good to get back on the winning track,” said Youkilis. “The team (Tampa) in front of us is picking up a lot of wins, so we have to play one day at a time. The biggest thing is we’re playing good baseball.”

The removal of Ramirez from the clubhouse isn’t the only factor why the Red Sox have been winning of late. Lowrie’s dynamic play has helped.

He was recalled from Pawtucket on July 12 when the Sox’ starting shortstop Julio Lugo suffered a quadriceps strain. Since then, Lowrie has started 11 of 13 games and has hits in nine of those games, going 11-for-38. His triple yesterday was the first of his major-league career, and he also driven in at least two runs in three straight games, including seven RBI.

His triple came in the fourth inning with the Red Sox holding a 1-0 lead thanks to Youkilis’ RBI in the first inning. With one out and two on, Lowrie drove a ball to deep center field that cruised over the head of Oakland’s Carlos Gonzalez.

“I was thinking sac fly and then I saw the ball was carrying,” said Lowrie. “It got over his head and I kept running. Once it gets into that corner you can run for days. I thought I’d done my job and it worked out better with the two RBI, and then I ended up scoring a run on Coco’s sacrifice fly.”

Boston had a 4-0 lead after four innings before the A’s pushed across a pair of runs in the top of the fifth. Crisp added his second sacrifice fly of the game in the sixth inning for a 5-2 lead, one the Sox would not relinquish.

It’s clear Lowrie is comfortable at the plate as he continues to come up with the timely hits and defensive plays. His approach is simple and he’s proven that he can handle playing every day at this level.

“I’ve always been of the belief if you put in the work and you maintain your approach, the results will be there in the end,” he said.

Yesterday morning Francona compared Lowrie to former Red Sox infielder Bill Mueller, who was a key component of the club’s World Series victory in 2004.

“He’s had some good at-bats,” said Francona. “He’s giving us a lot of production. In the limited at-bats (88 this season) he’s gotten some big hits and some timely hits. He’s just played the game. He’s blended in like our young guys do, and mixed in with the veterans, he’s helping us win.”

Boston’s manager isn’t the only one in the clubhouse to take notice.

“He’s doing a great job, man,” said second baseman and double-play partner Dustin Pedroia. “He’s making all the plays and swinging the bat great. I know we’re the same age (24), but he’s more mature than his age. He has stepped right in and we haven’t missed a beat. He’s picked us up when we’ve needed it. When Lugo went down, we knew Alex [Cora] and Jed needed to step up, and they’ve both done a great job.

Lugo said he is ahead of schedule with his rehab, saying he’ll be ready for September and the postseason. If Lowrie can continue his positive play then management will have an interesting decision on its hands. Like last fall when sparkplug rookie Jacoby Ellsbury replaced the struggling Crisp in Game Six of the ALCS, that could also be the case for Lowrie.

For now, however, he’s taking full advantage of his playing time.

“Any opportunity you get up here, no matter if it’s short or long, you want to show people what you can do,” he said. “I didn’t show up and say ‘This is my time.’ I just came here with the same approach I’ve had my whole career. If I do that the results will be there in the end.”

jmcdonal@projo.com