Dane Dunning (12-7) started on three days’ rest for Texas and worked 3 2/3 innings. He ran into trouble in the fourth with back-to-back singles by Eugenio Suárez and Jarred Kelenic and a walk to Ty France loading the bases.
Suárez scored on Dominic Canzone’s infield ground out, sliding just under Heim’s tag attempt at the plate.
Kirby had talked back in spring training of having a knuckleball in his pitch mix, but never threw it until the first pitch to Corey Seager leading off the fourth inning. Seager swung and missed at the 73 mph pitch.
Suárez, Seattle’s third baseman, and Texas shortstop Marcus Semien both finished the season appearing in all 162 games.
Suárez is the fifth different Mariners player to accomplish the feat an the first since Ichiro Suzuki in 2010.
Semien is the 11th Texas player to appear in every game and the second to start every game of the season in the field, joining Ruben Sierra in 1989.
Seager lost the AL batting title on the final day to Tampa Bay’s Yandy Díaz, who didn’t start in the Rays’ season finale. Seager went 0 for 4 and finished at .327. He started the day leading Díaz .3298 to .3295.
Seattle finished the regular season with an unofficial home attendance of 2,690,931. That’s a significant jump from 2,287,267 last season and the highest attendance for Seattle since 2,725,459 in 2005.
Mariners: Seattle’s spring training opener is on Feb. 24 against the Chicago White Sox.