SEATTLE -- With the way the Astros have been struggling to score runs in their last four games, they were left with little margin for error in Sunday afternoon's series finale against the Mariners at T-Mobile Park. The game seemingly hung in the balance with every pitch in the final few innings, and the Astros found themselves coming through in the clutch in some big moments.

The Astros avoided a sweep by eking out a 2-1 win over the Mariners, behind six strong innings from starting pitcher Luis Garcia, a solo homer by rookie shortstop Jeremy Peña and some huge outs by the bullpen. Yordan Alvarez came through with a big hit, too, for an Astros offense that has scored just five runs in the past four games.

Here’s a closer look at three moments that defined Houston's series finale win:

1. Montero works back-to-back strikeouts to end seventh
Relief pitcher Rafael Montero, traded to the Astros from the Mariners last July, has been terrific for Houston this season. Entering Sunday, his 0.48 ERA ranked third in the American League among relievers, to go along with a 0.86 WHIP and .167 opponents’ batting average.

So when manager Dusty Baker summoned him in relief of Garcia with runners at first and second base in the seventh inning of a tied game, the Astros appeared to be in good hands. A sac bunt by Adam Frazier pushed the runners into scoring position, and Montero struck out Mike Ford and Luis Torrens to end the threat.

“He came in and got big strikeouts and big outs and we needed that,” Baker said. “We certainly didn’t want to leave out of here with a sweep. We lost one game in the standings to them and scored three runs the whole series. That was very fortunate of us to leave out of here with a win.”

Upon getting the final strikeout, Montero quickly clapped into his glove while appearing to look towards the Mariners dugout. But Montero said he has no extra motivation against his former team and was just happy to get one of his biggest outs of the season.

“I thought it was a pretty big out for me and for the team,” Montero said. “Whenever I’m on the field, I always try to get the job done.”

2. Alvarez's go-ahead RBI single
The Astros were 0-for-15 with runners in scoring position in the series when Alvarez stepped to the plate against reliever Paul Sewald with the bases loaded in the eighth inning. Sewald had been having a hard time throwing strikes -- he walked the previous two hitters -- but Alvarez stayed aggressive.

With the Mariners employing a shift on the left-handed-hitting Alvarez -- and pinch-runner Aledmys Díaz dancing halfway down the third-base line -- Alvarez laced an RBI single on an 0-1 fastball into left field to score Díaz.

“Obviously, getting an extra-base hit would have been great there, but just put the ball in play and that’s what I did,” Alvarez explained. “I know [Sewald] is a really good pitcher against left-handed hitters [they were 4-for-19 against him] and gets a lot of them out, but I went up there positive and put it in my head that I was going to go up there to hit. I wasn’t looking to take walks.”

The Astros are hitting .169 (10-for-59) with runners in scoring position in their last nine games, including Sunday. They were 1-for-17 with runners in scoring position in their three games prior to Sunday’s series finale.

“That’s been eluding us for a while here,” Baker said. “That was big.”

3. Pressly gets the game-ending double play
Astros closer Ryan Pressly put himself in a bind when he walked J.P. Crawford to start the ninth. Crawford represented the tying run, and one out later the winning run was on first after Frazier singled. A walk to Ford loaded the bases and left Pressly with nowhere to put Torrens.

With the T-Mobile Park crowd smelling a sweep, Pressly got Torrens to hit into a game-ending 5-4-3 double play to win the game. Pressly gave an emphatic fist pump after first baseman Yuli Gurriel squeezed the final out at first base, giving him his eighth save in 10 chances.

“I’m just trying to make quality pitchers and execute them,” Pressly said. “I trust my defense, I think it’s the best defense in the league. And that gives you a lot of confidence to go out there and do whatever you want to do. Just felt like I was kind of all over the place, obviously, but you have to try to lock it in as best as you can.”