BOSTON -- You could either look at it as a classic case of cause and effect, or just two unfortunate half-innings that happened to fall on top of each other.

One thing is clear: An offensive squander in the bottom of the fifth inning followed by a pitching malfunction in the top of the sixth is what sank the Red Sox in Tuesday night’s 8-4 loss to the Rays at Fenway Park.

“That inning was kind of a momentum shift,” manager Alex Cora said. “Second and third, [nobody out], it doesn’t happen. Then, we walk the first guy and then they did what they did.”

The way the game started, it looked like it was going to be one of those wild Boston-Tampa Bay encounters of which there have been many in recent years.

The Rays scored three off Nick Pivetta in the top of the first. When Xander Bogaerts hammered a two-run homer to center (snapping a drought of 108 plate appearances without a long ball) in the first and Trevor Story lofted one over the Green Monster in the bottom of the second, it was suddenly a 3-3 game.

And that score was still on the board when the Red Sox came to bat in what wound up a fateful bottom of the fifth.

The rally that got away
Rob Refsnyder ripped a single to right and J.D. Martinez dropped in a double to right, and Boston had runners on second and third with nobody out.

It seemed like the deadlock was about to end, as the Red Sox had Bogaerts, Christian Vázquez and Story coming up against Rays righty Ryan Thompson.

On an 0-1 pitch, Bogaerts played into Tampa Bay’s drawn-in infield with a 69 mph grounder to second that gave Refsnyder no chance to advance.

“I’ve been doing that a lot this year. That’s not a good trait to have, I would say. It’s not a good approach to have,” Bogaerts said. “It’s not an easy pitcher either. If we had a pitching machine that could throw from the side, that’d be much better. But we don’t. It sucks, man. Not getting the run in, it hurts like you guys can’t even imagine.”

Then it was Vázquez with a chance to get the runner(s) home with less than two outs. He popped a 1-2 pitch to shortstop. Again, no advance.

“The last few days, even before the Cubs series, we haven’t done a great job with a man on third and less than two outs. We did an amazing job early in the season. The sac fly was probably our best play offensively the first month and a half,” Cora said.

That left it up to Story, who struck out on four pitches.

Pivetta’s streak ends abruptly
Not only is Pivetta the only Boston pitcher not to miss a start this season, but he was red-hot (8-1, 1.95 ERA) in the 11 starts that preceded this one.

After a rough first inning in which the Rays banged him around but then let him off the hook with a baserunning blunder, Pivetta steadied himself for four consecutive innings without allowing a run.

The momentum swung the other way again, starting with his leadoff walk to Wander Franco in the sixth. By the time the frustration-filled frame ended, the Rays had scored four runs, all of them charged to Pivetta.

“Obviously the leadoff walk [wasn’t good],” Pivetta said. “Middle-middle away to [Randy] Arozarena, probably not a great pitch there, missed location. Not very competitive pitches. Kind of on me in a sense of, if we hold that game to three, we probably win this game, because the bullpen comes into an easier situation than I led them into. So, chalk this one as on me, but we move on from here.”

Halfway home
Though it was a frustrating loss, the Red Sox reached the halfway point in a much better place than they were in at the quarter pole.

Despite not winning a series against an American League East team yet this season -- something that can change with a win in Wednesday’s rubber game -- Cora’s team is 45-36, and on pace for a 90-win season.

If the season ended now, the Red Sox would be in the playoffs. In fact, they’d be in line to host every game in a best-of-three Wild Card round.

“We’re in a good spot,” Cora said. “Overall, I’m not good at grades, but we are where we’re at. And I think we did an amazing job getting to this point. If you think where we were [10-19] on that [May 9] off-day going into Atlanta, we’re in a much better spot.”