After Fielder's tiebreaking single, a light snow shower passed briefly over Comerica Park. Jhonny Peralta added a sacrifice fly later in the inning, and Gerald Laird's RBI single gave the Tigers a three-run lead.
Phil Coke (1-0) pitched the eighth, and Jose Valverde finished for his first save of the season. Valverde blew a save for the first time since 2010 in Thursday's opener against Boston.
Austin Jackson homered for Detroit, which is the AL's last unbeaten team after handing the Rays their first defeat.
Rick Porcello allowed two runs and seven hits in seven innings for the Tigers in a game that began amid snow flurries with the temperature in the 40s.
In Baltimore, Raul Ibanez doubled in the tiebreaking run in the 12th inning, and the Yankees overcame a three-run deficit and a wild performance by starter Freddy Garcia.
Robinson Cano led off the 12th with a double off Pedro Strop (0-1). With two outs, Ibanez hit a liner off the right-field warning track that bounced into the stands.
Former Oriole Clay Rapada (1-0) got two outs in the 11th, and Mariano Rivera worked a perfect 12th for his first save this year and the 604th of his career.
Garcia threw five wild pitches, one short of the major league record. He yielded four runs, three earned, four hits and three walks in 4 2-3 innings.
In Toronto, Kyle Drabek pitched into the sixth inning and Edwin Encarnacion homered to lead Toronto to the victory.
Drabek (1-0) yielded one run and three hits in 5 1-3 innings, setting down nine straight in one stretch. He earned his first win since June.
Jason Frasor and Luis Perez each worked 1 1-3 innings and Casey Janssen gave up a two-run double to Adrian Gonzalez in the ninth before David Ortiz was caught looking at strike three, stranding runners at second and third.
In Arlington, Texas, Neftali Feliz pitched seven crisp innings in his first major league start and David Murphy had an RBI single for the only run in the Rangers' victory.
Feliz (1-0) allowed four hits, struck out four and walked two in his first game since the former closer failed to hold a two-run lead in Game 6 of the World Series. The Cardinals won in seven games.
This time, Feliz watched the bullpen close it out. Mike Adams pitched a perfect eighth inning, and Joe Nathan did the same in the ninth for his second save.
Feliz was a shade better than Blake Beavan, who was pitching for the first time in the ballpark where he grew up watching the Rangers.
Murphy had three hits and drove in the only run with an infield single in the second inning.
In Oakland, California, Danny Duffy pitched six sharp innings and the Kansas City beat Oakland in a rain-shortened game.
Mike Moustakas hit an RBI double in the fourth and Mitch Maier added a solo homer in the seventh for Kansas City, which lost 1-0 at Oakland on Monday night.
The start of the game was delayed 43 minutes by rain, and a steady drizzle continued throughout the night.
A second delay was called after Eric Hosmer struck out in the top of the eighth during a downpour. The bat slipped out of Hosmer's hands and landed just above the steps in the Royals dugout, prompting umpires to call for the tarp. The game was officially called at 11:07 p.m. local time.
Duffy (1-0) allowed one hit, struck out eight and walked four in his first game of the season. Aaron Crow pitched a 1-2-3 seventh for his first career save.
