SEATTLE -- Given Sean Manaea’s dominance through most of the 2021 season, it was probably only a matter of time before he got himself back on track. That he rediscovered his electric stuff at T-Mobile Park of all places, however, might not be a coincidence.

The four-game losing streak over five starts that Manaea carried into Thursday night’s contest against the Mariners was a career high for the left-hander. Returning to the site where he turned in his finest performance of the season last month, Manaea got himself right again by spinning seven dominant innings of one-run ball with a career-high 13 strikeouts in a 4-1 victory over the Mariners.

With most of the focus on catching the Astros for first place in the American League West, Thursday’s win to open a four-game series had a feeling of greater importance, as Seattle entered the night trailing Oakland by just 3 1/2 games for second place in the division.

For Manaea, while it wasn’t a shutout like the one he tossed against the Mariners in the same stadium on June 2, Thursday’s outing was one of the more dominant ones turned in by an A’s pitcher in quite some time. You’d have to go back to Todd Stottlemyre on June 16, 1995, to find the last time an A’s pitcher recorded at least 13 strikeouts while allowing one run or fewer in a start.

“You could see early on he was just pumping fastballs until they hit it,” A’s manager Bob Melvin said. “Then, all of a sudden, the changeup comes into play. His breaking ball is so much better than it was. When you’re able to throw that inside to a righty, it’s going to look like a fastball. He’s got a nice little mix going. He’s having a [heck] of a year.”

Manaea was feeling it early, finishing off a strikeout of shortstop J.P. Crawford with a 96 mph sinker that was the hardest pitch thrown by the 29-year-old lefty since May 30, 2018, when he threw a 98.9 mph heater against the Rays. The uptick in velocity set the tone for a brilliant stretch in which he retired 18 of his first 23 batters faced through six innings, matching his previous career high of 11 strikeouts over that period.

The extra life on Manaea’s fastball was evident throughout the night as it averaged 92.9 mph, which is more than a full mph higher than his season average (91.8 mph). The sinking fastball was used as the putaway pitch on seven of Manaea’s strikeouts and also generated 12 of his 21 total whiffs. It also played up his other two pitches, as his changeup produced six whiffs, while the curveball got three.

“I took a peek and saw 96 [mph]. I was pretty pumped about that because I don’t usually throw that hard,” Manaea said. “It felt good coming out of my hand, but I didn’t really expect to see 96. That was cool.”

Losing the shutout on a leadoff homer by catcher Tom Murphy in the seventh, Manaea quickly rebounded by striking out center fielder Jarred Kelenic. On his 106th and final pitch of the night, Manaea wrapped up his stellar performance by getting Crawford to swing through an 86.1 mph changeup for the final out of the seventh.

Manaea has proven to be a workhorse on the A’s staff, with Thursday’s outing falling in line with what he’s consistently done all season. He’s pitched into the sixth inning in 14 of his 20 starts to bring his innings total to 116 2/3, which ranks fourth among AL starters.

It’s been more than just the quantity for Manaea, though. After allowing just one run on three hits Thursday night, Manaea lowered his ERA to 3.16, which ranks sixth-best among AL starters.

“A lot of times it is velocity,” Melvin said of Manaea’s key to success this season. “He’s going to get a ton of swings and misses when he has good velocity, and his changeup is going to get just as many swings and misses because of his velocity. He’s just figured out how to pitch according to what he has on a particular day.”

Manaea’s two runs of support came on an infield single by Ramón Laureano in the fifth and back-to-back doubles by Mitch Moreland and Sean Murphy in the sixth. After Manaea departed, the A’s added some insurance with two runs in the eighth on another RBI single by Laureano, followed by Matt Olson’s sacrifice fly one batter later.

The A’s were hopeful to start off a daunting 10-game road trip that features eight divisional matchups on the right foot. Between Manaea’s brilliance, key late run production on offense and the bullpen’s ability to shut the door, Thursday’s win certainly qualifies.

“Giving the boys a chance to win is the ultimate goal,” Manaea said. “To do my job like that is huge. I know this is going to be a grind of a road trip. To start off like that is huge.”