Altuve's single, his third career walk-off hit and second of the season, prevented the Astros from losing a home series for the first time since dropping two of three to the White Sox on May 29-31.
He took Tigers reliever Alex Wilson's first pitch, a hanging cutter, and drove it to the left-center-field gap to score Jake Marisnick, who had laced a full-count, two-out triple off Tom Gorzelanny to prompt the pitching change.
"In those situations, everything looks strike, looks in the middle," Altuve said. "I'm a free swinger and everybody knows that, so I just swing the bat.