BOSTON -- Entering Thursday, the Rangers were 8-2 in games in which they scored eight runs.

With Texas holding a three-run lead going into the ninth inning of the series opener against the Red Sox, the Rangers appeared to be on their way to its ninth such victory. Instead, they found themselves on the wrong side of a 9-8 walk-off loss at Fenway Park.

Texas used five pitchers in the first of four games at Fenway: starter Glenn Otto, Jesús Tinoco, Matt Moore, José Leclerc and Jonathan Hernández. After Otto’s five-plus innings, Tinoco, who arrived Thursday as one of the Rangers’ two September callups, delivered two scoreless innings.

Moore surrendered two runs and recorded one out in the eighth before Leclerc finished the inning. And Hernández gave up all four runs in the ninth.

“We had a good start, had a good middle and handed the ball off to our three best guys the last two innings,” interim manager Tony Beasley said. “And they've been outstanding for us. Leclerc did a good job tonight, but, you know, Matt has been really good, and Johnny has been really good. Tonight just didn’t work out for those guys.”

Prior to Thursday, the trio of Moore, Leclerc and Hernández had yielded just three earned runs over their past 17 combined innings.

Though the lines were different, all five pitchers faced a similar struggle in walks. Together, the Rangers walked seven batters, marking the 10th time this season they’ve issued seven or more in a game. Texas now has 466 walks on the season, the third most in the Majors and the second most (behind Kansas City with 497) in the American League.

“The latter part of the game, the walks kind of got us and we allowed them to flip the lineup back to the top,” Beasley said, “To make that last inning, you're gonna face the heart of the lineup … that impacts the game at the end. Instead of facing the bottom half of the lineup, you're back to the top and those guys can put ABs on you.

“And [in] big moments, they know how to have a slow heartbeat and have a good at-bat. So you just got to keep attacking. … We’ve got to be more precise in those situations to make them earn everything.”

Otto had one of his best starts of the season, giving up three runs on four hits and one walk to go with a career-high eight strikeouts in his five-plus-inning outing. Over his past six starts, Otto has compiled a 3.31 ERA across 32 2/3 innings.

“I felt good, controlled a lot of counts,” Otto said. “I think that's what I'm capable of, I think that's what I'm looking to do every time out. Established the zone with the fastball and obviously, two spins that are pretty good, so yeah, felt good.”

While walks have been a problem for Otto this season -- he leads the team with 55 -- the right-hander issued just one to the Red Sox. After allowing a single to Alex Verdugo, Otto walked Xander Bogaerts on six pitches. Verdugo and Bogaerts came around to score on Christian Arroyo’s double before Otto retired the next batter to end the inning.

“It's part of the game,” Otto said. “It's not an easy game, by any means, especially at this level against this team in this atmosphere. So it's something that we got to learn from and move on, and continue to try to accumulate wins.”

Thursday marked the first time the Rangers have lost this season when their Nos. 1-4 hitters combine for eight hits. Marcus Semien went 3-for-5 with an RBI and a run scored, Corey Seager went 2-for-6 with two RBIs and a run scored, Texas’ August Player of the Month Nathaniel Lowe went 2-for-3 with two walks and a run scored and Adolis García drove in Lowe with his 22nd homer in the eighth inning.

“That’s what I have to do now, just put it behind, it's already happened,” Hernández said. “Tomorrow is another day, another opportunity. So I feel bad for tonight, but sometimes that's gonna happen. This is the game of baseball that we play. So just [move on], come back for the next one.”