Bart Bryant, Jeff Sluman, Bobby Clampett and Canada's Rod Spittle were a stroke back.
"It was a very solid day and again it just started great right from the start," Spittle said. "I drove it in the fairway all day, hit a whole bunch of greens and I hope to be equally as boring the next couple days so we can chat again."
Bryant birdied three of his final four holes.
"I had a little bonus by making about a 20-footer on the last hole," said Bryant, the Dick's Sporting Goods Open winner two weeks ago for his first Champions Tour title. "I didn't play the hole very well, but was able to make a birdie so that was kind of a bonus."
Michael Allen, Sandy Lyle, Scott Hoch, David Frost and Craig Stadler shot 65.
"There will be 15 or 20 guys with a chance to win on Sunday," Allen said "You want to get out and make some birdies and keep going right now."
Fred Couples opened with a 69.
The tournament is the 50-and-over tour's third event in Calgary. Don January won the 1983 Peter Jackson Champions at Earl Grey, and Brian Barnes won the 1998 AT&T Canada Senior Open at Glencoe.
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