Golf: A stunning back nine catapulted Bo Van Pelt into the lead after three rounds of the Canadian Open in Vancouver.

The American finished five-under par after his day's best round of 65 was pieced together on the back of a new Shaughnessy G&CC nine-hole record of 29 after the turn.

Van Pelt defied the high-scoring conditions on an unyielding layout as he fired six birdies on the way home to lead by a single stroke from local hopeful Adam Hadwin.

Hadwin, bidding to become the first Canadian to win their national title since 1954, had begun his round impressively with three birdies in his opening four holes to move up to five-under.

The 22-year-old, who is playing on a sponsor's exemption, had to battle thereafter though as he followed with three bogeys before scrambling back up the leaderboard with a pair of birdies at 12 and 16.

First-round leader Kris Blanks and Andres Romero were a stroke further back on three-under while veteran John Daly was an unlikely contender after his 67 left him three shots off the pace.

"You never know you are going to shoot 29," said Van Pelt. "You have to drive it in play. If you drive it in rough, you can't hit the green.

"I grew up on a tree-lined golf course with small greens, so from a visual standpoint, I like the looks of it."

The brutal rough on the tree-line Shaughnessy course again proved the undoing of a number of players and only 11 will enter the final day under par.

Overnight leaders Chad Campbell and Michael Thompson both registered four-over rounds of 74 to fall back to even while world number one Luke Donald and reigning Masters champion Charl Schwartzel were also notable contenders to struggle.

Englishman Donald shot a two-over 72 to slump to five-over for the tournament while Schwartzel, who had begun the day two off the lead, carded a 73 to be one over.

Two-time US Open champion Lee Janzen endured the worst round of the overnight contenders though, with a 76 dropping him from a stroke off the pace to three over.