BOSTON -- For the second time in three games, the Mariners' bats sizzled early before fading, allowing Boston’s offense to take advantage of pitching mistakes and handing Seattle a 6-5 loss at Fenway Park on Saturday.

Thursday night saw the visitors jump out to a four-run lead in the second inning, only to watch it dissolve by the end of the third before eventually falling, 12-6.

Saturday began with another four-spot, this time in the first frame when all nine batters came to the plate. Seattle would add to that lead when Luis Torrens drove in Mike Ford in the third inning, but that would be all the bats could muster on the day as Boston’s bullpen was up to the task of bailing out Red Sox starter Garrett Whitlock.

“We came out ready to go, had a great game plan against Whitlock,” said Seattle manager Scott Servais. “Our guys got on it early. You’re not going to do that every inning. Their bullpen threw the ball well, they’ve been throwing the ball all series against us. They have shut us down.”

Mariners starter Chris Flexen entered the game having received only five runs of support in his seven starts this season. He would get double that on the day, but against the dangerous Boston lineup, which got on the board via a solo home run from Rafael Devers in the third, his mistakes were unable to be masked as things unraveled quickly in the fifth inning.

Within the blink of an eye -- and only a matter of seven pitches -- the Boston bats knocked four consecutive hits to open the frame, including a two-run homer from Devers (his second of the game). Each of those batters would come around to score, leaving the game knotted up at five.

“Mistakes, and they hit every single one of them. It’s as simple as that,” said Flexen on what went wrong. “I was just trying to battle and maintain the lead, and I failed to do my job. ... I threw four different pitches, and all four of them were getting hit. I think it comes down to missing over the plate really bad, and they weren’t missing the mistakes.”

“He wasn’t fooling anybody today,” said Servais. “He was just trying to work through the lineup with what he had out there, and they were on him.”

Unlike Thursday night, the wheels did not completely fall off early, as the teams carried a tie into the eighth inning.

A leadoff triple by Franchy Cordero in the bottom of the inning, aided by a carom off the Green Monster that initially had center fielder Julio Rodriguez in the wrong position to field it, was followed up by Christian Vázquez's RBI single, which proved to be the winning run.

“That’s Fenway Park,” Servais said of the friendly bounce on the triple. “It’s going to bounce all over the place, it doesn’t work perfectly. It happens."

The Red Sox bullpen would face just one batter over the minimum from the fourth through the ninth. Additionally, Mariners batters struck out 11 times on the day, eight of those coming against the Boston relief corps.

“Unfortunately, Flex wasn’t able to get a little deeper into the ballgame,” said Servais. “They got on him in the fifth and it turned into a bullpen game after that. Their bullpen was one run better than us tonight.”

The Mariners have been stung by three straight losses at Fenway Park, where they will conclude their 10-game road trip looking to avoid the sweep on Sunday before heading home to face Oakland on Monday.