Detroit trailed 4-3 after Seattle's Dustin Ackley hit a three-run homer in the fifth, but Fielder's RBI single in the seventh tied it. Then he scored from first when Victor Martinez doubled off Charlie Furbush (2-6).
It was a busy day for Fielder, who appeared to take and eat a fan's nacho after unsuccessfully chasing a fifth-inning foul ball near the stands.
Torii Hunter homered for the Tigers. Doug Fister (13-9) struck out 10 in 7 2-3 innings. Drew Smyly got one out, and Joaquin Benoit pitched a perfect ninth for his 22nd save in 22 chances.
Detroit pushed its AL Central lead to 6 1/2 games. Second-place Cleveland hosted Houston on Thursday night.
Detroit shortstop Jose Iglesias left after being hit around the left wrist by a pitch in the sixth inning. X-rays were negative.
In the top of the fifth, Fielder chased after a foul ball that dropped near the stands. Before returning to his position, he took what looked like a nacho from one of the fans near the front and ate it, while receiving a pat on the back from another fan.
Fielder doubled in the third and fifth. After Hunter led off the Detroit seventh with a double and went to third on Miguel Cabrera's flyout, Fielder hit a single to make it 4-all.
Martinez, who had already been intentionally walked twice, followed with his second double of the game - to the corner in left field.
Fielder, who was thrown out at home on a similar play to end a game against Kansas City last weekend, was called safe this time, although Seattle argued.
Seattle scored a run in the first on an RBI single by Raul Ibanez. Hunter tied it in the bottom half with a solo shot, and Martinez added an RBI double later in the inning.
Seattle intentionally walked Martinez in the third with men on first and second, but starter James Paxton walked Omar Infante on four pitches to force in a run and make it 3-1.
Fister allowed four runs and nine hits with one walk. His only major mistake was a pitch to Ackley in the fifth that the Seattle outfielder hit over the wall in right for his fourth homer of the year.
Paxton allowed three runs and five hits in five innings.
NOTES: Martinez, normally Detroit's DH, started at catcher for the third time this season. ... Tigers pitchers have 1,323 strikeouts, five more than the previous team record set last year. ... Detroit hosts the Chicago White Sox on Friday night. Tigers RHP Max Scherzer (19-3) faces RHP Andre Rienzo (2-2). Seattle RHP Erasmo Ramirez (5-2) faces Los Angeles Angels RHP Jered Weaver (10-8).