SEATTLE — All the Mariners offense needed to get back on track was to face the middle of Baltimore’s bullpen.

Seattle’s lineup is one of the majors’ worst this season despite the club’s standing atop the American League West. The Mariners own an MLB-low .216 batting average while averaging more than 10 strikeouts per game.

Their woes reached a crescendo this week against the Orioles, tallying two hits Tuesday and scoring only one run across the series’ first two games — both Baltimore wins — as boos reigned down from Seattle fans at T-Mobile Park.

But the Mariners’ bats put on a fireworks show in Thursday’s seventh inning, scoring five runs off Orioles relievers Bryan Baker and Keegan Akin to hand Baltimore a 7-3 loss and avoid a series sweep.

“A really poorly pitched seventh there,” manager Brandon Hyde said.

Baker loaded the bases and was replaced by Akin with two outs for a left-on-left matchup against leadoff hitter J.P. Crawford. After falling behind the count 3-0, Akin fed Crawford a center-cut fastball that the shortstop crushed to right-center field for a bases-clearing double. Five pitches later, designated hitter Mitch Garver provided insurance with a two-run blast to further spoil ace Corbin Burnes’ solid start.

Hyde often uses his southpaws to face left-handed batters, hoping to use the handedness advantage to piece together the end of games. With Akin this season, that’s backfired several times, and Thursday was the latest example. Crawford, who entered the game with an OPS nearly 200 points better versus lefties, laced his 107.4 mph double to score Baker’s three runners who reached base via a Julio Rodríguez double and a pair of walks around two punchouts.“Bring the lefty in and fell behind 3-0 and center-cut a fastball,” Hyde said. “Didn’t execute well that inning.”

The Orioles’ bullpen has mostly held up this season, entering Thursday with a 3.51 ERA that ranked seventh in the majors. After the Fourth of July folly, Baltimore’s relief corps fell to 12th with a 3.64 mark. The club’s middle relief has been especially shaky in recent weeks, a worrying trend that could be ameliorated at the trade deadline.

Baltimore is 55-32 and still two games up on the New York Yankees atop the AL East. The Yankees were swept this week at home by the Cincinnati Reds and have lost 13 of their past 17 games.

Burnes pitched well enough to win. Six days after his wife Brooke gave birth to twin girls Charlotte and Harper, Burnes delivered his 14th quality start in his 18th outing this season. The right-hander sports a 2.32 ERA in his first year in Baltimore after the club acquired him this offseason.

Gunnar Henderson was a triple away from the cycle to lead Baltimore’s offense. In the third, he clobbered a two-run home run to left field — staying inside a middle-in slider — to give the Orioles a 2-0 lead, one that disappeared in the fifth when the Mariners scored two runs off Burnes.

“Rockets all over the field,” Hyde said of Henderson’s hard-hitting afternoon. “Home run that’s like a right-handed hitter pull-side homer. It’s a joke what he can do.”

Rodríguez led off the inning with a solo homer after Burnes retired the previous 12 batters in order.

Seattle loaded the bases with no outs, but Burnes artfully escaped the jam, only allowing one additional run on a ground ball double play.

“We made some big pitches when we needed to,” Burnes said. “One mistake there to Julio, just a poor cutter, but after that, to get out of it with only one run given up, big double play there, was big.”

Around the horn

Ryan Mountcastle didn’t start Thursday for the fourth time in five games as he manages an unspecified illness. Manager Brandon Hyde said he was “easing” the first baseman back into game action.

The Orioles’ rotation is remaining in turn for the club’s series in Oakland against the Athletics. Albert Suárez, Cade Povich and Grayson Rodriguez will start the three games in order beginning Friday. Cole Irvin is now in the bullpen with Dean Kremer back healthy.

Triple-A Norfolk manager Buck Britton will throw to Henderson at the Home Run Derby on July 15, Mid-Atlantic Sports Network broadcaster Geoff Arnold said on the Orioles Radio Network during Thursday’s game.

Norfolk utility player Billy Cook, the Orioles’ No. 29 prospect per MLB Pipeline, was placed on the injured list Thursday with a right hamstring strain. Cook, who has played six defensive positions this season, has an .802 OPS with the Tides.