Edmonton's Kevin Martin hammered Norway's Thomas Ulsrud 5-1, while Glenn Howard of Coldwater, Ont., needed an extra end to defeat Toronto's Mark Kean 5-4.
World champion Niklas Edin of Sweden, Canadian champion Brad Jacobs of Sault Ste. Marie Ont., and Winnipeg's Jeff Stoughton are among the big names entered in this week's competition at the Mattamy Athletic Centre, the former site of Maple Leaf Gardens.
The women's field is as deep as the men's competition.
World champion Eve Muirhead of Scotland is one of the headliners along with national champion Rachel Homan of Ottawa and veterans Jennifer Jones of Manitoba and Heather Nedohin of Alberta.
A combined event purse of $200,000 is on the line at this week's bonspiel. An additional Grand Slam combined bonus of $200,000 will also be awarded.
Epping upset Howard in last year's TPC men's final in Summerside, P.E.I. Saskatoon's Stefanie Lawton defeated Winnipeg's Cathy Overton-Clapham for the women's crown.
Preliminary-round play continues through Friday. The quarter-finals and semifinals are on tap Saturday and the finals are set for Sunday.