WASHINGTON — Outfielder Jason Repko’s bid to make the opening-day roster for the Boston Red Sox finished with quite a flourish.

He drove in the go-ahead run in the top of the ninth inning, then threw out a runner at the plate for the game’s last out, and the Red Sox beat the Washington Nationals 8-7 Tuesday in the exhibition finale for both clubs.

“I worked hard and showed how I can help the team win, and it’s in their hands, and I try not to spend too much time thinking about it,” Repko said.

Asked whether he’d be heading to Detroit with the Red Sox, who open at the Tigers on Thursday, Repko replied: “I think it’s up in the air. We’re minute to minute.”

He’s played in six major league seasons with the Dodgers and Twins, limited to 67 games with Minnesota in 2011 because of several injuries. He signed a minor league deal with the Red Sox last month in hopes of making the roster as someone able to play all three outfield positions. He hit .289 this spring and stole seven bases.

“He’s absolutely been in the mix from the beginning, and today he gets the big hit in the game and in a big stadium makes a perfect throw,” manager Bobby Valentine said. “He’s only done everything we’ve asked him to do.”

Jacoby Ellsbury and Dustin Pedroia sure looked ready for the regular season in front of a crowd of 30,568 at Nationals Park, combining for four hits, four RBIs and four runs — helping Boston take a 6-0 lead — before taking the rest of the cloudless afternoon off.

“I left a couple balls up in the zone with runners on base and they took advantage of it thanks to Dustin Pedroia — he drove in most of the runs,” Nationals starting pitcher Edwin Jackson said.

Jackson gave up six runs and five hits in 4.2 innings, with one walk, one wild pitch and two strikeouts.

Alfredo Aceves, a candidate to replace the injured Andrew Bailey as Boston’s closer, pitched a scoreless eighth for the win. Bailey will have reconstructive ligament surgery on his right thumb today and will be out at least several months.

Chorye Spoone threw the ninth for the save.

Red Sox starter Clay Buchholz cruised through four perfect innings before allowing Adam LaRoche’s leadoff single in the fifth and, four batters later, Wilson Ramos’ three- run homer. Desmond started Washington’s sixth with a solo shot.

Buchholz went 5.2 innings and gave up four runs and four hits. He didn’t walk a batter and struck out five.

“That’s the best I’ve felt all spring,” Buchholz said.