Ogwumike scored 10 in the final quarter as the Sparks (11-14) moved three games ahead of the Storm (9-18) for the fourth and final Western Conference playoff berth.
Crystal Langhorne scored 21 and Camille Little added 16 to lead Seattle, which has lost five straight and six of seven.
Toler had lost her first two games after she took over July 20 following the dismissal of coach Carol Ross.
The Sparks are 4-0 against Seattle this year and have clinched any potential tiebreaker.
The Storm look to snap their losing skid Tuesday on the road against Tulsa.