The Sarnia Sting lost 5-2 in Kitchener Friday night.
Sarnia led 1-0 after the first when Easton Wainwright (7) scored at the 8:20 mark.
The Rangers replied in the second period with goals from Trent Swick, Reid Valade and Matthew Sop.
The Sting's Ty Voit (24) made it 3-2 at the 15:01 mark of the third period on the power play before Mike Petizian scored the insurance goal into the empty net for the Rangers followed by another empty netter from Joseph Serpa.
Benjamin Gaudreau made 32 saves for the Sting while Kitchener netminder Pavel Cajan blocked 29 shots.
Sarnia remains in the eighth and final playoff spot in the OHL's Western Conference with 57 points, one point ahead of idle Erie, with four games remaining in the schedule.
The Otters visit Flint Saturday while the Sting are in Flint Sunday.