Gold River, California's John Catlin shot a 7-under 63 at Highland Country Club in London, Ontario on Thursday to take the first round lead at the Freedom 55 Financial Championship, the final event of the 2015 Mackenzie Tour – PGA TOUR Canada season.

The second year Mackenzie Tour player carded eight birdies to offset a single bogey on Thursday to build a three-shot advantage over six players, including Order of Merit leader J.J. Spaun, Canadians Max Gilbert and Riley Wheeldon and Americans Ben Geyer, Michael Miller and Logan McCracken.

"I tried to go out and have fun today. I think I've been taking it too seriously, and I just tried to enjoy every shot and take it all in. I hit a lot of good shots and made some good putts," said Catlin, who enters the week 42nd on the Order of Merit with two top-10s to his name.

The 24-year old University of New Mexico grad said the pristine greens at Highland freed him up with the putter and helped him build his lead, the largest first-round lead of the PGA TOUR era on the Mackenzie Tour.

"Putting was definitely the key. It's good to be on some really good greens. I was seeing the lines really well and they happened to go in for me," said Catlin.

For much of Thursday, it appeared Order of Merit leader J.J. Spaun would keep pace with Spaun and take control of his money list lead, reaching 7-under with a birdie on the 14th. Spaun tumbled with a bogey and double bogey over his final three holes, however, to drop back into a tie for second at 4-under.

"I just made some dumb errors coming in, but there's nothing I can do about it. At least I'm in a good position heading into the next three rounds," said Spaun.

Gilbert, the 2013 Freedom 55 Financial Championship winner, posted his lowest opening round of the year with a 66 to share second place through one round.