LOS ANGELES -- The Mariners had everything lined up in their favor.

The offense briefly awoke from its slumber to score three quick runs and give the Mariners an early lead. They had a red-hot Bryce Miller on the mound working on a lengthy scoreless streak. They had a rested bullpen with all of their top relievers ready to go.

And yet, it still wasn’t enough to lift the Mariners out of their disastrous spiral.

All-Star reliever Andrés Muñoz surrendered a tiebreaking, three-run homer to Jason Heyward in the bottom of the eighth inning as the Mariners suffered a crushing 6-3 loss to the Dodgers at Dodger Stadium. The Mariners have lost seven of their last eight games and missed an opportunity to gain a game on Houston in the American League West standings, as the Astros lost to Boston earlier in the night.

"It's a grind,” Miller said. “We're 100 and something games in. We know we’ve got to get it going. Hopefully, we turn it around soon.”

Jorge Polanco staked the Mariners to an early 3-0 lead with a two-run single in the first and an RBI double in the third. Miller worked out of trouble through the first three frames to extend his scoreless streak to 16 innings. At that point, everything appeared to be going the Mariners' way.

Instead, it fell apart spectacularly.

The offense failed to add on and the Dodgers chipped away. Miller served up solo home runs to Gavin Lux and Max Muncy in the fourth to shrink the lead to 3-2 and end his scoreless streak. He was pulled after throwing 92 pitches in four innings, tied for his shortest outing of the season.

"I didn't have any clean innings,” said Miller, who allowed five hits and two runs. “Every inning was like 25 pitches. I feel like I made a lot of good pitches, but they hit a lot of foul balls. I couldn't get any quick outs.”

Seattle's relief corps held serve in the middle innings, but the Dodgers eventually broke through.

The Mariners went on the aggressive in the seventh, bringing in their closer, Muñoz, with Tommy Edman on second base with one out as the tying run and the top of the Dodgers' order due up.

But instead of stemming the Dodgers' rally, he amplified it.

Muñoz gave up a smoked liner to Shohei Ohtani that Justin Turner picked out of the air at first base for a lineout, but Mookie Betts promptly rocketed an RBI double down the left-field line to tie the score.

Out in right field, Mitch Haniger stepped up to prevent any further damage. Teoscar Hernández grounded a hard single into right field off Muñoz, but Haniger fired a perfect 95.6 mph strike to the plate to nail Betts trying to score. The throw ended the inning and kept the score tied at 3-3.

Instead of supplying the Mariners some much-needed momentum, however, it just delayed their collapse.

Despite giving up three hard-hit balls, Muñoz came back out for the eighth and struggled again. After hitting Will Smith with a pitch and walking Muncy, he left an elevated 99 mph fastball high and inside that Heyward pummeled over the fence in the right-field corner for a pinch-hit, back-breaking, go-ahead three run homer.

"I just threw my pitch and he hit it,” Muñoz said. “I threw my best pitch. He hit it. It is what it is.”

Heyward’s homer left his bat at 107.7 mph, a ringing blow that sent the Dodger Stadium crowd into a frenzy and the Mariners into a state of zombified shock.

"They're just really good hitters and they won this time,” Muñoz said. “That's all I have to say. I threw good pitches. I feel I threw how I was supposed to throw. But they are good hitters, and they won."

The Mariners still trail the Astros by five games in the AL West. They were 44-31 with a 10-game lead in the division on June 18.

Now, they are just a game over .500 and playing for their postseason lives. Though the coaches and players are striking an upbeat tone, they know time is running out to turn their season around.

"It’s one thing if you go out and you’re not really in the game and you just get beat,” manager Scott Servais said. “We were in the game the whole night tonight, and even at the end, we put the pressure on them late. Focus on where we're at in the moment. We played a good game today. We've got to come back tomorrow and do it again."