TORONTO (Interstat) — In a postseason duel defined by dominant pitching and timely hitting, the Seattle Mariners seized the initiative in their American League playoff series, defeating the Toronto Blue Jays 3-1 on Sunday at a sold-out Rogers Centre.

Facing a hostile crowd of 44,474 and a pregame projection that heavily favored the home team, the Mariners leaned on a masterful performance from starter Bryce Miller and a decisive two-run sixth inning to secure a crucial victory in Game 1. The win gives Seattle an early edge as the series shifts back to the Pacific Northwest.

The Blue Jays, installed as 1.5-run favorites by oddsmakers, struck first and fast. Lead-off hitter George Springer jolted the home crowd in the bottom of the first inning, launching a solo home run to right field off Miller to give Toronto an immediate 1-0 lead. The Jays threatened to add more, drawing a walk from Nathan Lukes and another from Addison Barger, but Miller escaped the jam without further damage by inducing a flyout from Alejandro Kirk and a sharp lineout from Daulton Varsho.

From that point forward, Miller was virtually untouchable. The Seattle right-hander settled into a dominant rhythm, silencing a potent Toronto lineup. After Springer’s first-inning homer, the Blue Jays managed just one more hit against Miller—a single by Anthony Santander in the second inning that was aided by a fielding error. Miller efficiently worked through six complete innings, allowing just the one earned run on two hits while striking out three. His command and poise set the tone for the Mariners’ entire pitching staff.

“He just got stronger as the game went on,” a Mariners team official said of Miller’s performance, echoing the sentiment in the visiting clubhouse. “After that first inning, he was in complete control.”

For five innings, Toronto starter Kevin Gausman matched Miller zero for zero. The Mariners had opportunities, putting two runners on in the first inning, but Gausman worked out of trouble and held Seattle to just three hits through the first five frames, striking out five.

The stalemate was broken in the top of the sixth. After two quick outs, Seattle catcher Cal Raleigh stepped to the plate and connected on a towering fly ball that carried into the seats in right-center field for a solo home run, tying the game at 1-1. The blast seemed to energize the Seattle dugout. Julio Rodríguez followed with a walk, and Jorge Polanco delivered a clutch line-drive single to left field, scoring Rodríguez from first base to give the Mariners a 2-1 lead and chase Gausman from the game.

Gausman was charged with the loss, his record falling to 11-12. He finished with a line of 5.2 innings pitched, allowing two earned runs on three hits with five strikeouts.

Seattle added a critical insurance run in the top of the eighth inning. Facing reliever Brendon Little, Randy Arozarena worked a lead-off walk and advanced to second on a walk to Rodríguez. Polanco came through once again, this time with a ground-ball single to right field that scored Arozarena, extending the Mariners’ lead to 3-1. Polanco finished the day 2-for-4 with two crucial RBIs.

The Mariners’ bullpen, one of the league’s best, took over from there. Gabe Speier worked a perfect seventh inning, and Matt Brash followed with a 1-2-3 eighth, each recording a strikeout. In the ninth, All-Star closer Andrés Muñoz entered and retired the side in order, securing his 40th save of the season and sealing the victory for Seattle.

The win improved the Mariners’ overall record to 94-74, while the Blue Jays fell to 97-70. The victory was a statement for a Seattle team that had lost two of three to Toronto in their most recent regular-season series in May.

The two teams will reconvene at Rogers Centre for Game 2 on Monday. The Mariners will look to take a commanding 2-0 series lead before the scene shifts to Seattle, while the Blue Jays will be desperate to even the series on their home field.