On a windy day at Richardson Stadium, McMaster quarterback Andreas Dueck completed 25 of 41 pass attempts for 256 yards and was intercepted twice.
He also ran for Mac’s only touchdown of the game, a one-yard score that put the Marauders up 10-5 midway through the third quarter.
Queen’s QB Alex Vreeken went nine for 25 for 100 passing yards and one interception, and rushed five times for 14 yards including a three-yard major that gave the Gaels a 12-10 lead early in the fourth quarter.
McMaster’s defence recorded four sacks and Josh Cumber had an interception.
The Marauders can clinch the final playoff spot in the OUA with a win over the University of Toronto Blues (3-4) in their regular season finale on Saturday, Oct. 22.