In addition to entering the US with your Canadian passport you'll also need to use that passport to check in for your flight to the US. Otherwise, the airline would require you to have valid ESTA authorization. By checking in with the Canadian passport you will avoid any confusion.
It should not really matter where you're coming from. If you apply for admission with your Canadian passport, all you have to do is comply with the requirements for Canadian citizens entering the US. So, if Canadians need a ESTA, you'll have to apply for one.