In Detroit, Jack Morris won his 10th straight, on a six-hitter. Tom Brookens and Chet Lemon helped with homers.
Morris (18-8) struck out five to increase his league-leading total to 194. Morris twice has won 17 games, but never before has he won more.
"I've never had a guy pitch with this magnitude, never," Manager Sparky Anderson of the Tigers said. "With the situation we're in, though, he can't lose. I mean he will, but he can't."
"We had to win tonight," Morris said. "It's been that way the last two times out for me. Even though Chet was the hero with that ninth-inning homer Sunday, I had to keep them in it.
"It's that time of year, I guess, where you have to reach down inside yourself and get the job done."
Brookens hit his sixth homer of the season in the second inning, with two out and none on.
In the Detroit fifth, a single by Lou Whitaker, a walk to Alan Trammell and an infield single by Larry Herndon loaded the bases. Lance Parrish drove in Whitaker with a chopper back to starter Frank Tanana (7-6).
Lemon hit his 20th home run, a single-season high for him, leading off the sixth.
The Tigers scored twice in the eighth on an RBI single by Lemon and an RBI double by Glenn Wilson.
Rangers shortstop Bucky Dent was hit on the left side of the head by a thrown ball during infield practice. He was removed from the starting lineup and taken to a Detroit hospital for X-rays. Wayne Tolleson played in his place.