Hamilton clubbed a towering leadoff shot to center in the seventh, pushing the Texas advantage to 7-4, while Fielder's RBI groundout in the eighth made it a two-run contest.
Joe Nathan struck out two in a 1-2-3 ninth for his 17th save of the year.
Earlier, Fielder ripped a two-run double into the gap in left-center for a 2-0 Detroit advantage in the opening frame, but Ian Kinsler, mired in a 2-for-21 slump, helped the Rangers cut the deficit in half as he launched a leadoff homer over the wall in left to make it 2-1 after an inning of play.
Detroit got the run back in the fourth when Fielder cracked a solo blast over the wall in left center, giving the Tigers a 3-1 lead.
Joe Nathan struck out two in a 1-2-3 ninth for his 17th save of the year.
Earlier, Fielder ripped a two-run double into the gap in left-center for a 2-0 Detroit advantage in the opening frame, but Ian Kinsler, mired in a 2-for-21 slump, helped the Rangers cut the deficit in half as he launched a leadoff homer over the wall in left to make it 2-1 after an inning of play.
Detroit got the run back in the fourth when Fielder cracked a solo blast over the wall in left center, giving the Tigers a 3-1 lead.