BOSTON — It isn’t always possible to identify a game’s turning point, particularly in the early innings, but the Mariners made that easy to do Saturday in a 6-2 loss to the Boston Red Sox.
The Mariners built a 2-0 lead through two innings for rookie Adrian Sampson in his big-league debut. It could have been more. They settled for one run in the first after loading the bases with no outs.
No, that wasn’t it.
The game turned in the third inning after the Mariners put Boston starter Rick Porcello (8-2) on the ropes when Leonys Martin led off with a single and went to third on Seth Smith’s double.
The Mariners had the meat of their order lined up.
And got nothing.
Porcello struck out Robinson Cano and Nelson Cruz before ending the inning by retiring Kyle Seager on a grounder to second. Porcello settled into a groove thereafter and pitched through the sixth with little trouble.
"Rough," Cruz said. "We should be able to score more runs in those situations. We had the guys we want up there. Unfortunately, we didn’t make it happen."
It was pretty much all Boston after Porcello’s third-inning escape.
"We felt good about the guys we had coming up," manager Scott Servais said, "and what we had going there (in the third inning). You’ve got to give credit to Porcello. He made some pitches.
"He elevated some fastballs by our guys in spots when he needed to do it."
The Mariners promoted Sampson (0-1) early Saturday from Triple-A Tacoma as a replacement for Wade Miley, who went to the disabled list Friday because of a sore shoulder.
Sampson worked his way through three scoreless innings before the American League’s top-scoring attack got going.
"It’s a special place to start your (major-league) career," Sampson said. "After the first inning, I settled in pretty good. I just think toward the end of the game, I had some bad misses."
Jackie Bradley Jr. hit a homer in the fourth inning before the Red Sox knocked out Sampson with a three-run fifth while taking a 4-2 lead. Boston added runs in the sixth and eighth against Mike Montgomery.
Junichi Tazawa, Koji Uehara and Craig Kimbrel closed out the victory.
The Mariners had a chance to present Sampson with a big early cushion when they opened the game by loading the bases against Porcello on singles by Martin, Smith and Cano.
They settled for one run.
Cruz grounded into a run-scoring double play, and Seager popped to left.
"We have struggled recently with men on third and less than two outs," Servais said. "We’ve got to be a little more proficient at that. Those are big parts of the game. We’ve got to add on."
Sampson then yielded singles to three of the first four batters in his first big-league inning but, thanks to a double play, wiggled free without damage.
Adam Lind’s leadoff homer in the second inning made it 2-0. It was a 444-foot bomb that cleared the 17-foot wall at Fenway’s distinctive triangle in center field.
After the Mariners squandered their big chance in the third, Boston pulled to within 2-1 when Bradley crushed a 2-1 fastball for a two-out homer in the fourth inning.
The ball cleared the 37-foot Green Monster in left-center field.
The Red Sox opened the fifth inning with singles from Chris Young, Christian Vazquez and Mookie Betts. That tied the game at 2-2 and put runners at first and third with no outs with the heart of the order coming up.
Dustin Pedroia grounded into a double play, but Vazquez scored, and the Red Sox led 3-2. Xander Bogaerts followed with a homer on an 0-2 fastball — a third straight fastball — that just cleared the wall.
That finished Sampson and, really, the Mariners.
"He hung in there," Servais said. "He probably wasn’t as sharp as he normally is. It’s his major-league debut. There are going to be a lot of butterflies. He gave us a chance.
"We had opportunities to score a few more runs early and just didn’t get it done."
PLAY OF THE GAME: Shortstop Ketel Marte committed a two-base, run-scoring error in the eighth inning when he failed to catch a throw from Robinson Cano.
Hanley Ramirez was on second after a leadoff double when Jackie Bradley Jr. lined out to Cano, who then threw to second in an attempt to double up Ramirez. Marte didn’t catch the ball, which scooted into short left field.
"I didn’t see anything after Robby threw it," Marte said. "I thought that ball was going to be in my face."
Ramirez popped up and scored ahead of the throw home by left fielder Nori Aoki.
"(Marte) just lost the ball," Servais said. "The 4 o’clock start here is challenging. If you look at the angle that ball is coming at him, it’s coming right out of the crowd. He never saw it."
PLUS: With the Red Sox over-shifting their infield to the right side in the fifth inning, Seth Smith pushed a 1-0 off-speed pitch up the third-base line for a bunt single. It was his third hit of the game…Leonys Martin had two hits in four at-bats and is 6-for-20 over his last five games…Adam Lind had a homer in four at-bats and is batting .419 (13-for-31) in his last 10 games at Fenway Park.
MINUS: Ketel Marte’s error was his 11th of the season, which leads all American League shortstops…the Mariners allowed 12 hits, which marked their third straight game of allowing at least 11…the core of the Mariners’ lineup — Robinson Cano, Nelson Cruz and Kyle Seager — were a combined 1-for-12.
STAT PACK: The Mariners are 6-11 in June and, since June 2, have dropped from a tie with Texas for first place in the American League West Division to 7 1/2 games behind the Rangers.
QUOTABLE: Nelson Cruz on what makes Boston starter Rick Porcello a challenge for hitters: "He can command the sinker. And then when he throws the heater, it has some (upward) carry. He’s a tough pitcher to face."
SHORT HOPS: Adrian Sampson was the first Mariners player to make his major-league debut at Fenway Park since shortstop Alex Rodriguez on July 8, 1994…Mariners closer Steve Cishek turned 30 on Saturday…the Mariners have hit at least one homer in eight straight games against Boston.
Bob Dutton: @TNT_Mariners