BOSTON -- Tanner Houck, perhaps now in the rotation for good, did his part to give the Red Sox a shot at winning Thursday’s key rubber match against the Rays.

But Boston’s offense was shut down a day after a 20-run outbreak, and the Sox endured an 8-1 loss at Fenway Park that dropped them five games back of Tampa Bay for the American League East lead. After recording 19 hits in Wednesday's 20-8 win, the Red Sox managed only two hits in the series finale.

• Box score

“They pitched. We didn’t put the ball in play,” Boston manager Alex Cora said. “Just part of baseball, I guess. It wasn’t a good day offensively overall the whole day. As a team, it wasn’t great after [Wander] Franco hit the home run.”

In the big picture, however, the Red Sox look like they have a 25-year-old right-hander they can count on the rest of the season.

Houck, Boston’s No. 6 prospect per MLB Pipeline, looked electric over the first five innings, allowing only one unearned run, which Rafael Devers offset with a booming RBI double into the right-center-field gap in the fourth.

The turning point came in the top of the sixth, when the Rays seized the momentum with two quality at-bats. It started with Brandon Lowe opening the inning by working a seven-pitch at-bat for a single.

Up next was the 20-year-old Franco, who looked like a 10-year veteran by working an 11-pitch at-bat that culminated with one of the quirkiest home runs in the history of Fenway Park. Franco belted a 3-2 sinker that caromed from the left of the yellow line on the Green Monster and bounced right to the top of the shorter wall in center for a two-run homer.

The yellow line is used to differentiate between base hits off the wall and home runs. Balls to the left of it are still in play, provided they do what they have done in just about every case before and carom back on the field. But this one took a random bounce for a unique homer that put the Red Sox in a 3-1 deficit.

If such a homer has ever been hit at Fenway Park, nobody could seem to recall it.

“They always talk about [it] with the [ground] rules with the umpires,” Cora said. “High wall to the little wall, [home run] or whatever. I’m like, ‘Yeah, right. I’m never going to see that.’ And it happens. That’s a first. Now, I’m looking for somebody to hit the ladder in left field to see what happens there.”

It stands to reason that Houck and Franco could have many more battles in the coming years. Houck will try to get even next time.

“Made some pitches, and he fouled off some good pitches that I can’t complain about,” Houck said. “I made a mistake on the 11th, but that’s part of it. You’re not going to be perfect every time, so it was just a mistake.”

"I was looking for a pitch to hit in the zone,” Franco said. “He was throwing me in. He was throwing me out. So I was just trying to stay calm and just trying to keep myself and the ball in the zone."

Despite the misfire, the Red Sox remain impressed by Houck’s arsenal and composure.

“His stuff was good. He was commanding the zone really well, getting quick outs, and threw the ball well, but Franco put a good at-bat together,” Red Sox catcher Kevin Plawecki said. “It’s really as simple as that. You’ve got to tip your cap. We made good pitches. We tried to go sinker there. He kind of left it in the middle, and [Franco] put a good swing on it. He beat us there. It’s as simple as that. But Houck threw the ball great.”

In his first nine Major League starts -- six of which have come this season -- Houck has a 2.27 ERA.

“This guy is going to compete,” Cora said. “He has great stuff. He’s going to give us a chance to win.”

While Houck is likely to be optioned to Triple-A Worcester by Friday for roster flexibility reasons, the Red Sox are going to bring him back as the 27th man so he can start one of the games in Tuesday's seven-inning doubleheader at Yankee Stadium.

“I’m looking forward to whatever challenge is thrown at me, honestly,” Houck said. “Being a part of it is exciting, but also one of those things where you continue to show up every day and put in the work that got me to this point and just continuing down that trend and not letting your foot off the gas.”