OAKLAND -- The game was officially lost when Austin Voth surrendered a 418-foot walk-off homer to Shea Langeliers in the bottom of the ninth inning. But that fateful, punctuational moment in the Mariners’ deflating, 5-4 defeat on Monday afternoon at the Coliseum might’ve been avoided altogether had it not been for three critical strikeouts from Seattle’s bats the half-inning prior.

Victor Robles, J.P. Crawford and Julio Rodríguez went down in order against rookie reliever Tyler Ferguson, prompting Mariners manager Dan Wilson to turn to Voth instead of closer Andrés Muñoz, who was warming and would’ve been installed with a lead.

Voth grinded into a full count against Oakland’s slugging catcher, but paid mightily for a sweeper he hung over the heart of the plate, watching the ball stay just inside the left-field foul pole while sailing into the second deck.

Metaphorically, with another stinging defeat, the Mariners might be watching their season slip away.

“[Stuff] hasn’t gone our way,” said Crawford, who is 0-for-14 since returning from the injured list last Wednesday. “We’ve just got to keep going though. We can’t give in.”

Seattle fell back to .500 (69-69) for just the second time since April 12 and has lost 13 of its past 19 games and 12 of its past 14 on the road. Each of its past five defeats have been by one run, underscoring just how sour this stretch has been.

The more telling statistic among the unflattering is that the Mariners also fell to 5-10 since the All-Star break on the same day that the Astros lost -- excluding head-to-head matchups -- illustrating just how challenging they’ve made it for themselves to gain ground in the American League West.

Houston fell to Cincinnati earlier on Monday, but retained a six-game lead atop the division. The Mariners also had a chance to inch closer in the AL Wild Card race after Kansas City, which holds the final playoff spot and sits 5 1/2 games ahead of Seattle, lost to Cleveland.

There are 24 games remaining, and it’s going to take a run that the Mariners haven’t yet shown all year to extend their season into October. Their longest winning streak this season is four -- done six times -- which they’ll almost certainly have to surpass to get back into the race.

“Just flush it,” said Logan Gilbert, who struck out nine over six innings. “That’s our job. That’s what we have to be able to do.”

To be sure, the A’s are much-improved since the last time the Mariners played here in early June, advancing to 23-17 on Monday since the All-Star break, the AL’s second-best record in this stretch to only Houston. Their .430 slugging percentage in this period ranks ninth, boosted by Langeliers’ walk-off and a three-run, go-ahead blast he hit off Gilbert in the third.

The first homer was arguably more costly, as it was set up by production entirely with two outs. Gilbert gave up consecutive doubles, to Lawrence Butler and Brent Rooker, then walked JJ Bleday before the big blast from Langeliers. Each of those hits was against his slider, all three of which leaked over the plate and up.

“My direction, I felt, was a little off on that,” Gilbert said. “I didn't really get my hand out front and left it over the middle.”

Most of the Mariners’ shortcomings this season have been rooted in their inconsistent offense, and strikeouts in each of their final five at-bats further underscored those issues. Yet until that point, they’d only K’d six times and found much more traction at the plate -- beginning with a booming, two-run homer from Cal Raleigh in the first inning.

But its pitching has been on the hook for just as many hiccups on this road trip, which began with the club dropping two of three in Anaheim over the weekend. Across these four games, the Mariners have given up 10 homers, the most in MLB since Friday.

Seattle’s struggles have spanned the entire roster over the past three weeks, which reached a tipping point when Scott Servais was relieved of his duties as manager on Aug. 22 and replaced by Wilson. Yet, as Monday showed, many of those issues still remain -- and with time running out to fix them.