HOUSTON -- If you ask Astros manager Dusty Baker, starting pitcher Framber Valdez opened Game 2 of the American League Division Series “like a house on fire” on Thursday at Minute Maid Park. But it didn’t exactly last the entire outing.

The left-hander cruised through three innings against the Mariners, allowing just one baserunner -- a two-out double from J.P. Crawford in the third -- before his sharpness started to waver. Valdez gave up two hits and a walk and committed a throwing error in the fourth inning but managed to escape the frame with just two runs allowed.

Those two runs (one earned) ended up being the only damage against Valdez over 5 2/3 innings, as he kept the game within striking distance even after laboring through the long fourth inning and helped the Astros to a 4-2 victory over the Mariners.

“I feel pleased with my outing, especially given the fact that I haven't pitched in about 10 days,” Valdez said. “I wouldn't necessarily say I felt comfortable throwing to [the Mariners], but it was all about the focus. I was very focused today, and I felt confident in all my pitches -- my sinker, my curveball and my changeup -- to throw all those pitches for strikes. I was able to get to the sixth inning and keep the game where it was and give the team a chance to win.”

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In nine career appearances against Seattle entering Thursday, Valdez had gone 5-0 with a 1.94 ERA over 51 innings. Though he wouldn't reveal the game plan for yet another matchup with the AL West foe, Valdez relied heavily on his curveball, throwing the pitch 46 percent of the time (42 of his 92 pitches). He typically throws the curve 28.1 percent of the time, with the sinker (49 percent) his dominant pitch.

“His curveball was just really good today; the sinker is always really good, and we threw a couple changeups too,” catcher Martín Maldonado said. “Framber, he can throw any pitch, in any count, to any batter.”

“Framber was good,” Baker added. “I mean, he came out locating his fastball. His fastball was almost a little too hard, because he was throwing 94, 95 [mph]. Usually, he's 92 to 94 with movement. But he was good. I mean, he held us in the game until the big boy [Yordan Alvarez] hit one out.”

The unsung hero of the ALDS so far has been the Astros’ bullpen, which has limited the Mariners to just one run over 8 1/3 innings across the first two games.

On Thursday, the bullpen only allowed one hit, a double to Julio Rodríguez in the ninth inning.

"The job for the bullpen is to … shut out the game, and if you’re behind in the game, to keep it in line,” said veteran reliever Héctor Neris, who was credited with the winning decision in his first postseason appearance. “We’re trying to get 27 [outs]. The bullpen is part of the starter, and it’s important every time.”

Neris could also be credited with saving the game in the sixth inning after Valdez walked the bases loaded with two outs and the Astros down by one run. Neris entered and quickly induced a groundout from Cal Raleigh to keep the game within reach.

Baker noted that while the relievers have been getting out of trouble easily, he could tell some of them were a bit rusty entering the series.

“Yeah, they did a great job getting out of trouble, and [Maldonado] did a great job of directing them out of trouble,” Baker said. “You don't invite that kind of trouble and have them get out of trouble all the time like that. It's been a while since [the relievers have] been out there. So hopefully, in the ensuing games, we'll be better.”