BOSTON -- The innings were adding up. The Phillies had scored three runs in the first frame of Tuesday's win over the Red Sox, but after four innings on Wednesday, they had yet to get back on the board.

That is, until Bryce Harper stepped to the plate in the top of the fifth.

Entering Wednesday's series finale, Harper had never recorded a hit against Red Sox starter Rick Porcello in Interleague Play.

That changed with one swing of the bat -- a monster, two-run swing at that. After seeing three straight four-seam fastballs (and fouling off two), Harper rocked an 86.6-mph slider 377 feet over the Green Monster in left field at 101.3 mph, according to Statcast, during the fifth inning of the Phillies' 5-2 win.

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The Phillies improved to 66-60 and have won six of their last eight games. They remain 1 1/2 games back for the second National League Wild Card spot.

"He's the guy on the team," Phillies starter Drew Smyly said of Harper. "He's going to help carry us. His swing was huge, obviously, to take the lead."

Including his first-inning groundout Wednesday, Harper had struck out in three of his eight at-bats against Porcello. The Red Sox righty had a strategy to counter the heavy-hitting Harper, and it didn't go as planned.

"Yeah, it was supposed to be backdoor," Porcello said. "Got him out on the first at-bat and he put a good swing on it. It was a little bit lower than we'd like to throw it. We were in a good, favorable count and we had some options that we could have wasted some pitches, see if he'd chase, do some different things. We went with that and he got it. It was a good swing. Just needed to be a better pitch."

The opposite-field shot was Harper's 22nd home run in Interleague competition, and his third in 11 games against the Red Sox. He belted his only other homer at Fenway Park on June 8, 2012, as a member of the Nationals. Harper came close in the '15 season opener in Boston, but Mookie Betts robbed him at the bullpen with a stellar catch in center field.

There were fans in the crowd who were trying to distract Harper from snapping that Fenway Park home run streak, too. Harper was met with boos during the two-game series in Boston, and his ability to block out the noise and go yard for his 27th home run of the season stood out to Phillies manager Gabe Kapler.

"I thought it was really interesting: There were some hecklers," Kapler said. "I don't know if they were Red Sox [fans] or who they were, but they were on him pretty good up until that moment. That was a pretty explosive moment for the dugout celebration."

The Phillies are 59-33 when they hit at least one homer. When it comes to their home run leader, they are 19-6 when Harper knocks one out of the park. And those games are quickly adding up. Harper has homered in four of his last seven contests, with 12 RBIs during that time.

"Really happy for Bryce to come up big in that moment," Kapler said.