Sinches' third score of the game capped a 21-point fourth quarter as the Yellow Jackets (2-0) rallied for the win.
Sinches finished with 28 carries.
Trevor Hudson contributed 41 yards on seven carries and one TD for Quitman, while quarterback Tyler Drennon passed for 83 yards on four completions.
Eric Hughes totaled 60 yards on two receptions.
Lance Evans rushed for 248 yards on just 13 carries to lead Quitman (0-1) in the Bulldogs' season opener. Evans scored on runs of 39, 93 and 58 yards.
Devonte McNeil added 56 yards on eight carries.
Mineola plays host to Grand Saline this Firday.
Quitman travels to take on Frankston Friday night.