Lamaze, from Schomberg, Ont., rebounded from five faults in the first round with a clear second round aboard Powerplay at the 1.6-metre event.
Also riding for Canada were Olympians Ian Millar of Perth, Ont., Vancouver's Tiffany Foster and Mac Cone of King City, Ont.
Ireland won the event with just four faults through two rounds, while the United States followed with nine faults.
Canada stumbled with 13 faults in the first round before recovering with just one fault in the second.
Lamaze, Millar and Foster were part of the Canadian team that finished fifth at last year's London Games. Lamaze won a silver with Millar and Cone at the 2008 Beijing Games.