BOSTON -- When Friday’s rained-out series opener was rescheduled for Monday afternoon, the Rays weren’t necessarily thrilled about extending their week-long road trip and losing a scheduled day off. But that change did bring about one positive development.

They got to send their ace to the mound in the series finale. And Shane McClanahan made sure the Rays went home happy.

McClanahan became the first pitcher in the Majors to reach nine wins and lowered his ERA to an American League-best 2.02 after holding the Red Sox to just one run over six innings in the Rays’ 4-1 victory at Fenway Park.

“If we're going to have to work on an off-day, we might as well win, you know?” Luke Raley said. “We won. That's all that matters.”

And that’s what usually happens when McClanahan takes the mound for Tampa Bay. The left-hander has allowed two runs or fewer in 12 of his 13 starts, and the Rays have gone 11-2 behind him this season.

Coming off his first loss of the season Tuesday night in Chicago, McClanahan allowed five hits and two walks while striking out five. His ERA is the lowest by a Tampa Bay starter through 13 outings in a season, behind only himself in 2022 (1.84) and Chris Archer in 2015 (1.84), and the Braves’ Bryce Elder (1.92) is the only pitcher in the Majors this year with a lower ERA than McClanahan.

“He's just really good,” manager Kevin Cash said. “He's been on a good run.”

When the Rays arrived in Boston, McClanahan was scheduled to get six days of rest before starting Tuesday’s series opener against the Twins at Tropicana Field. But Friday’s rainout and the decision to play on Monday’s mutual off-day forced the Rays to shuffle their plans. 

So the Rays pushed McClanahan’s outing up a day, still giving him five days’ rest but slightly altering his routine and changing which lineup he’d be facing. McClanahan insisted Sunday morning that the switch wouldn’t be an issue.

“I’m ready,” he said, smiling. “I don’t think you guys should worry.”

Indeed, there was no reason for concern. 

McClanahan was frustrated after walking two of the first three batters he faced, but he immediately induced a double play from Rafael Devers to get out of the inning then retired 13 of the next 16 hitters before giving up a solo shot to Justin Turner in the sixth.

“After that first inning, I was really committed to just getting ahead and staying ahead and then making quality pitches in and out of the zone,” McClanahan said.

Devers singled to center after Turner’s home run, and the Rays bullpen began to stir as McClanahan’s pitch count crept into the 90s. But McClanahan promptly coaxed a ground ball from Masataka Yoshida that Vidal Bruján -- called up Monday morning to replace the injured Brandon Lowe -- turned into a slick, inning-ending double play.

McClanahan pumped his fists and shouted as he walked off the field, a celebration meant entirely for Bruján.

“I made sure he knew that he saved my butt right there,” McClanahan said.

The Rays’ other defensive highlight came in the eighth, when reliever Colin Poche struck out Devers and catcher Francisco Mejía caught Alex Verdugo stealing second to end the inning.

“Bru was outstanding. Awesome play,” Cash said. “That play and Frankie's double play on the throw-out, those were the two biggest plays of the game.”

The Red Sox robbed a pair of would-be homers by Raley and Mejía to keep the Rays off the board early and extend their season-long homer-less streak to four games. But they eventually broke through against Boston starter Brayan Bello with a three-run fifth keyed by Raley’s leadoff double, run-scoring hits from Manuel Margot and Mejía, and Josh Lowe beating a double-play grounder to drive in another run.

The Rays won the final three games of this four-game set in Boston to secure their first series victory on the road since taking three of four against the White Sox from April 27-30. They have won seven of their eight games against the Red Sox, whom they won’t face again until Labor Day, clinching the season series for the fifth straight year and the seventh time in the last 10 years.

But after five days in Boston that included an off-day, a rainout, a scheduled doubleheader, chilly weather and a lot of rain, the Rays were eager to fly home Monday night.

“We're ready to get back to the Trop,” Raley said.