Myers finished with a game-high 31 points, five of which came in the extra period.
Sunshine rallied from eight points down in the final quarter to force overtime and clinch the win. Sunshine forced the overtime on a free throw by Deborah Lewis with 58 seconds remaining in regulation.
Tara Mullinax led Spring Garden with 24 points, and Jordan Sides had 11. Kelsey Turner chipped in a game-high 12 rebounds.