Walker (1-2), making just his third start with the Dragons, allowed only two base runners and no runs over the first six innings. His final line over six and two-thirds included four hits and two runs (one earned) with one walk and seven strikeouts.
The Dragons took the lead in the top of the first inning when Cody Puckett doubled to left, stole third, and scored on Carlos Mendez's ground out to make it 1-0.
In the top of the seventh, Dragons catcher Chase Weems doubled to left with the bases loaded to drive in two more runs and make it 3-0.
Great Lakes scored two runs in the bottom of the seventh, but the Dragons answered with one in the eighth when Mendez singled, went to second on a hit by Byron Wiley, to third on Humberto Sosa's sacrifice, and scored Tony Brown's sacrifice fly to make it 4-2.
Great Lakes scored against Dragons reliever Mike Bohana in the bottom of the eighth. Dayton reliever Jordan Hotchkiss came out of the bullpen and worked out of a bases loaded jam in the eighth, then pitched a scoreless ninth for his third save.
Dayton finished with nine hits. Mendez, Wiley, and Kevyn Feiner each had two.
The Dragons 2010 schedule will be announced later this week. The Dragons will start spring training at the Cincinnati Reds new spring complex in Goodyear, Arizona in March, 2010.