HOUSTON -- Seattle Mariners right-hander Felix Hernandez endured his fair share of problems in two prior starts against the Houston Astros, yet entering the sixth inning Tuesday night, he found a groove befitting his ace status.

Then, he collapsed.

Rookie Alex Bregman emerged from a two-week injury hiatus and delivered a game-tying, pinch single with two outs in the sixth to ignite a six-run frame that pushed the Astros to an 8-4 victory over the Mariners at Minute Maid Park.

Bregman, sidelined by right hamstring discomfort since Sept. 15, dumped a curveball into center field off Hernandez (11-7) to even the score at 4-4. The floodgates opened from there, with George Springer and Marwin Gonzalez producing two-run base hits to chase Hernandez and complete the onslaught.

"It's pretty rough not being able to go out and compete with your brothers, and coming up like that and to come through with a hit to tie the game was awesome," Bregman said. "It felt great."

The Astros (83-75) pulled within 2 1/2 games of the second American League wild-card spot with the victory. The Baltimore Orioles (85-72) maintain that position despite falling 5-1 to the team holding the top wild-card place, the Blue Jays (87-70). Toronto holds a two-game edge on the Orioles.

Baltimore is one game in front of the Detroit Tigers (84-73) and two up on Seattle (83-74).

"Obviously we're not dead yet," said Springer, who finished 3-for-5 and scored twice. "This team isn't going to quit. We're going to go down fighting, and this is a big game for us. Now we've got to move to tomorrow and have ourselves another day."

Hernandez had allowed just one hit between Evan Gattis' infield single with one out in the first inning and the Astros' rally in the sixth. Bregman followed a two-out walk from Tony Kemp and preceded Jake Marisnick reaching on the Mariners' second error of the inning.

Springer and Gonzalez then doubled and singled as Houston became the first team to score six-plus run off Hernandez, who allowed eight runs (four earned) on 10 hits and two walks, in three consecutive games.

"I'm not going to say it's not a good lineup," Hernandez said. "I just have to throw different pitches and have a different approach, and I will be fine."

The Mariners, who led 4-2 in the third, fell to 16-16 over their past 32 games.

Houston right-hander Jandel Gustave (1-0) earned his first major league win after throwing 1 1/3 scoreless innings in relief.

Astros right-hander Mike Fiers started slowly, surrendering eight hits over his first 15 batters. Seattle strung together three consecutive hits in the first inning, with Nelson Cruz following a Robinson Cano double with an RBI single to center field.

With one out in the second, Jesus Sucre and Ketel Marte produced back-to-back singles to set the table to the top of the Mariners' order. Nori Aoki dropped a run-scoring double over Springer in right field before Seth Smith followed with a sacrifice fly to center that scored Marte, who scampered to third on the Aoki double.

Fiers allowed one more hit, an RBI double to Lind with one out in the third inning, before closing his outing with a flourish by retiring the final seven batters he faced.

Fiers gave up four runs on eight hits with five strikeouts in five innings. He appeared set to absorb the loss before Marte and Lind erred in the sixth to benefit the Astros.

"It's part of the game," said Cano, who went 2-for-4 with two doubles. "You don't want to blame anybody. They took their chances when we gave them chances and took advantage. They got the big hit and took advantage when we made mistakes."

NOTES: After not factoring in the decision Monday thanks to a two-run, ninth-inning rally, Astros RHP Collin McHugh remains undefeated in 13 September starts since 2014. McHugh is 11-0 with a 3.05 ERA in September with the Astros, including 3-0 with a 3.10 ERA this month. ... The Mariners trio of 2B Robinson Cano, DH Nelson Cruz and 3B Kyle Seager are in contention to become the first American League teammates to record 30-plus doubles, 30-plus home runs and 100-plus RBIs since the 2001 Athletics (Eric Chavez, Jason Giambi, Miguel Tejada). ... Astros 3B Alex Bregman was a full participant in batting practice and was scheduled to take a flight to Florida so he could continue his rehab at the club's spring training complex in Kissimmee, Fla. However, he will remain with the team following his pinch hit in the sixth inning.