The Rays are six games behind the American League East-leading Yankees and six games behind Baltimore for the second AL Wild Card spot with 14 games left on the schedule.
"We're just not playing well now," Rays manager Joe Maddon said.
Until Jeff Keppinger singled to start the bottom of the eighth, the Rays' odd line on the scoreboard appeared to be a mistake: five runs on two hits and three errors.
Ben Zobrist had both hits -- a pair of two-run singles coming in the third and seventh innings, with an Evan Longoria sacrifice fly accounting for the other run.
"Offensively, we scored five runs on three hits," Maddon said. "We did take advantage of some of their wildness early on, but again, we have to be better in all facets of the game."
On a night when the Rays' much-maligned offense clearly maximized the potency of two singles, the team's pitching staff, beginning with starter Jeremy Hellickson, struggled.
After posting three scoreless frames and holding a 3-0 lead, Hellickson surrendered one in the fourth and two in the fifth before leaving the game with a no-decision after just four-plus innings and 94 pitches. The Rays went 4-1 in Hellickson's first five starts of the season and are just 8-15 since.
"Jeremy had great stuff, not good stuff, great stuff," Maddon said. "So it all began there. He had that 3-0 lead and he just could not throw the ball for a strike when he wanted to, but he normally can. ... I thought he looked great, then that went away."
Jake McGee took over for Hellickson and retired the three hitters he faced in the fifth along with the leadoff hitter in the sixth before giving way to Kyle Farnsworth, who allowed singles to Ryan Lavarnway and Scott Podsednik. A groundout moved the runners into scoring position, and Farnsworth appeared to escape the jam when he got Pedro Ciriaco to ground to third, but Sean Rodriguez uncorked a wild throw to first. Lavarnway scored on the play and the Rays actually got a break.
Rodriguez's throw escaped Keppinger at first, but it rebounded off Red Sox first-base coach Alex Ochoa back to Keppinger, who threw to Chris Gimenez at the plate. The Rays catcher tagged out Podsednik for the third out, which would have given the Red Sox a two-run lead.
"The first-base coach made a great play for us there," said Maddon, allowing himself a chuckle.
For Rodriguez, who was activated from the disabled list after suffering a fractured bone in his right hand when he punched a locker, the error was his fourth in two nights.
"I don't think [Rodriguez's hand is an issue]," Maddon said. "He's done well. He's fine. He hasn't played in a while, that part is defendable, but those are plays he normally makes."
The Red Sox added three in the seventh against Wade Davis when Jarrod Saltalamacchia singled home one and Lavarnway added a two-run double to push the lead to 7-3.
"Salty got a big hit," Red Sox manager Bobby Valentine said. "Ryan Lavarnway, big hit for Ryan. He's been kind of searching for that one. Two strikes, he kept battling and drove in the runs. That was big."
The Rays' best chance to get something late in the game came in the seventh when Zobrist singled home two to cut the lead to 7-5. But Longoria grounded out with two aboard to end the threat.
The Rays began September 4-0, but they have gone 3-9 and dropped four games in the AL East standings. Maddon can only hope his club manages to find a way to re-route their fortunes with the sand running rapidly out of their hour glass to make the playoffs.
"We just have to go out and play Wednesday, man," Maddon said. "I don't have anything brilliant to say. We're not playing well and we have to figure it out relatively quick."