BOSTON — The Tampa Bay Rays fell 6-1 at Fenway Park on Sunday, completing a four-game series sweep by the Red Sox and extending Tampa Bay’s losing streak to a season-high five straight games.

The sweep fed Boston’s 13-game winning streak, tied for the second-longest run in franchise history, while the Rays absorbed their fourth sweep of the year. Tampa Bay’s starters allowed five or more runs in each of the five consecutive losses — a stretch that began before the Boston series.

“It’s a talented team that kind of went through it early on in the season, and they’ve come out on the other side of it,” Rays manager Kevin Cash said. “We kind of caught the brunt of it.”

The rotation’s collapse was thorough. Right-hander Griffin Jax gave up seven runs in five innings in Friday’s 10-0 opener. Mason Englert allowed five in five innings in the doubleheader nightcap. Lefty Ian Seymour exited Saturday after surrendering three runs in three innings. And in Sunday’s finale, Shane McClanahan gave up six runs — four earned — on five hits and three walks over five innings in his first start since July 8.

“The body felt great. Arm felt great. Obviously, those 10 days [are] great for the body, but really bad for the routine,” McClanahan said. “Just looking forward to getting back [to] normal and having that routine and getting some things cleaned up.”

McClanahan didn’t get much defensive support. In the third inning, the Red Sox scored three runs without a hit — only the fifth time that has happened in the expansion era — aided by a passed ball from catcher Hunter Feduccia and a throwing error by third baseman Junior Caminero. Cash called the inning decisive: “The third inning seemed to kind of define the outcome of the game right there. We had opportunities, didn’t capitalize. They had opportunities and did capitalize.”

“I point to every facet of our game,” Cash said. “We just weren’t playing as clean of baseball, whether it was on the mound, at the plate or on defense.”

The offense was equally lifeless. The Rays finished Sunday hitless in 15 at-bats with runners in scoring position and stranded 11 men on base. The top of the lineup went cold across the series: Yandy Díaz, second in the American League with a .310 average, went 1-for-16 (.063) with two walks, while Jonathan Aranda was 1-for-12 (.083) with two walks.

“It’s just a bad moment, right? That’s all it is. It’s a bad moment,” Díaz said through interpreter Kevin Vera. “We’re trying to do everything that we can to win, obviously, but it just hasn’t come through.”

The Rays’ first five-game skid since April 2-8, 2025, leaves them searching for answers heading into the week. Tampa Bay won’t face Boston again until Sept. 18-20, the final regular-season series of the year at Tropicana Field.