Fraley robbed Isaac Paredes of a game-ending homer with one out in the ninth, reaching well over the left-field fence to make the catch, then threw to first for an inning-ending double play.
''We were playing no-doubles depth, so that was huge,'' he said. ''That meant I could get back to the fence a lot quicker than I normally could have, but that's still a catch you might make once out of 10 times - it is just trying to time it perfectly and give myself a chance.''
After both teams scored one run in the 10th, Fraley gave the Mariners a 5-4 lead with a one-out RBI single in the 11th.
Daniel Norris (0-2) hit Taylor Trammell, loading the bases, and Shed Long Jr grounded into a forceout at the plate. Dillon Thomas boosted the lead to 7-4 with a two-run single for his first major league hit, and Tom Murphy hit a two-run double for a five-run lead advantage.
Robbie Grossman led off the bottom half with a two-run homer off Kenyan Middleton, who allowed a single and then retired three batters in order.
''Obviously, this is a disappointing one,'' Tigers manager A.J. Hinch said. ''We thought the game was over, but they made an incredible defensive play and then we couldn't finish it off in extra innings.''
JT Chargois (1-0) won after throwing a run-scoring wild pitch in the 10th.
Both starters were aided early by spectacular catches in the opening innings. Tiger center fielder Derek Hill robbed Kyle Seager of an RBI double in the first, crashing into the fence to make a leaping catch. Hill left after the play with a sprained right shoulder.
Seattle's Chris Flexen got his help in the second when, with a runner on third and two outs, Thomas, a 28-year-old making his major league debut after 10 minor league seasons, jumped against the right-centerfield scoreboard to take extra bases away from Niko Goodrum.
''He's spent 10 years playing in the minors and in independent ball, so he's got a lot of life experience and game experience,'' Mariners manager Scott Servais said. ''You could see that tonight.''
Detroit built a 3-0 lead on Jonathan Schoop's sacrifice fly in the third, and Jake Rogers' homer and Grossman's RBI single in a two-run fifth.
Seager hit a three-run homer in the sixth off Casey Mize.
''It's frustrating,'' Mize said. ''Derek makes that catch and gets knocked out of the game, and the offense scores three runs. That has to be enough for me.''
Mariners: Thomas was the 50th player used by the Mariners this season, five more than any other major league team.
Tigers: CF Daz Cameron was removed from Wednesday's game with Triple-A Toledo and will be available if Hill goes onto the injured list. Hinch said they were expecting test results late Wednesday night.
Tigers assistant hitting coach Jose Cruz Jr. will leave the team next week to become the new head coach at Rice.
The teams finish their three-game series on Thursday, with Seattle's Justus Sheffield (5-4, 4.77) facing a Tigers opener expected to be Tyler Alexander (0-0, 4.56).
More AP MLB: https://apnews.com/hub/MLB and https://twitter.com/AP-Sports
Copyright 2021 STATS LLC and Associated Press. Any commercial use or distribution without the express written consent of STATS LLC and Associated Press is strictly prohibited.