Mike Zunino homered and had three hits for the Mariners, right in the middle of a crowded race for the second AL wild card. They used seven pitchers to hold down the Yankees, who lead the wild card race but trail first-place Boston by 41/2 games in the AL East.
Alonso entered as a pinch hitter in the ninth and sent a drive to center field with two outs in the 11th against Chapman (4-3), the $86 million reliever who recently lost his job as closer. The struggling lefty was booed again as he walked off the mound after the inning.
Acquired from Oakland this month, Alonso became the third left-handed batter to homer against Chapman in his eight-year career. Just 12 days before, 20-year-old Boston rookie Rafael Devers became the second.
James Pazos (4-4) tossed a perfect inning against his former team, and Edwin Diaz got three outs for his 30th save.
Todd Frazier flied out to deep left and Brett Gardner later stole second before Diaz fanned Aaron Hicks on the next pitch for the final out.
New York stranded 13 runners and left the bases loaded three times — twice on strikeouts by Frazier, batting ninth for the first time in his career.
One day after brawling with the Tigers in Detroit, Yankees catchers Gary Sanchez and Austin Romine were among four players suspended by Major League Baseball. Sanchez was banned for four games and Romine two, but both appealed — keeping them eligible to play until the process is complete.
Sanchez nearly hit an early grand slam, but his two-out fly was caught in the left field corner.
Seattle loaded the bases with one out in the ninth, but Ben Gamel fouled out and pinch hitter Robinson Cano struck out on three pitches against Dellin Betances.
A buzz went up in the crowd of 42,057 when Cano stepped into the on-deck circle to get loose. He wore a teal and light blue Mariners jersey on Players Weekend with "Don't You Know" written across the back, the nickname (sort of) given to him by New York radio broadcaster John Sterling when Cano played in pinstripes.
Fans roared when Betances made quick work of the former Yankees star, who didn't start due to a tender hamstring.
Wearing the nickname "Dub" on the back of his blue and gray jersey, CC Sabathia was in top form for the Yankees. The big lefthander allowed only Zunino's 19th homer in seven sharp innings. He gave up five hits and struck out six on "Star Wars" night at the ballpark.
With the Yankees trailing 1-0 in the eighth, Aaron Judge drew a one-out walk from ex-New York reliever David Phelps. Didi Gregorius lined a double to left-center, where center fielder Guillermo Heredia booted the ball as he tried to cut it off. The error allowed Judge to score the tying run.
Gregorius made an ill-timed running blunder when he got thrown out at third trying to advance on a grounder to shortstop. Two more walks by Phelps loaded the bases before Nick Vincent struck out Frazier to end the inning.
Sabathia and the Yankees caught a break when Heredia's two-out double in the second bounced over the wall for a ground-rule double, preventing Zunino from scoring from first.
Seattle starter Ariel Miranda was pulled with a 1-0 lead in the fifth, one out shy of qualifying for a win. He walked four and left the bases loaded twice, throwing only 52 of 99 pitches for strikes.
Mariners: Cano left Wednesday's game in Atlanta with tightness in his left hamstring. "He feels OK," manager Scott Servais said. "Just play it safe." Heredia was back in the starting lineup. He was removed Wednesday after getting hit on the right forearm by a pitch.
Yankees: All-Star 2B Starlin Castro was reinstated from the disabled list and doubled in the fourth for New York's first hit. Castro had been sidelined since July 23 and missed 31 games with a strained right hamstring. Castro was a little shaken up after smothering a hard grounder with his chest in the 11th, but stayed in the game. With the Yankees facing a lefthander, 1B Greg Bird (right ankle surgery) remained on the DL, though it sounds as though he's about ready to be activated.
Seattle sent OF Leonys Martin outright to Triple A Tacoma. ... To make room for Castro, the Yankees optioned INF-OF Tyler Wade to Triple A Scranton/Wilkes-Barre.