The Canadian crew finished first in the K-4 500 metres in one minute 36.495 seconds.
Cuba finished second followed by Argentina.
Michelle Russell of Fall River,N.S., Emilie Fournel of Montreal, KC Fraser of Oakville, Ont., and Hannah Vaughan of Dartmouth, N.S., edged the Cubans by 1.17 seconds.
"I can't describe it," said an overwhelmed Russell. "I can't find the words to describe how it feels to win gold, in the Pan Am Games, in Toronto, on home soil, the very first medal. I can't."
The race was the first final of the Games, which officially opened Friday in Toronto.
"We always race at this course but today was a really special occasion," said Fraser. "There was more family, more everybody. Everybody's here to watch what we do and it's great. I think just today, on home soil, made it that much more special."
It's a promising start for the Canadian team, which has set a goal of finishing in the top two in the overall medal count.
Canadian chef de mission Curt Harnett has estimated the host team of 719 athletes needs to rake in about 200 medals over the 16 days of competition to hit that target.
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