Will MacKenzie surges late at The McGladrey Classic to share the lead

MacKenzie - who has not won on the PGA Tour since 2008 - birdied the seventh and ninth holes to card a five-under 65, joining Brian Harman, Michael Thompson and Erik Compton at the top of the leaderboard.

The American quartet hold a one-shot lead over another seven of their compatriots in Georgia, plus South Korea's Park Sung-joon.

Chesson Hadley, Shawn Stefani, Andrew Svoboda, Patton Kizzire, Jason Kokrak, Jim Renner and John Peterson sit alongside Park.

Having teed off on the back nine at Sea Island Golf Club, MacKenzie dropped two shots on the 16th hole to fall back to even par but a birdie on the par-four 18th set up his round.

The 40-year-old American then birdied the first and second holes, before his strong finish dragged him into a share of the lead.

Harman also started on the back nine and finished strongly with four birdies on his last seven holes as the 27-year-old aims for his second PGA Tour victory of the year, after taking out the John Deere Classic in July.

Compton and Thompson started their tournaments on the first hole and both dropped a shot on the back nine to miss the chance of claiming the outright lead.

Reigning champion Chris Kirk had a tough start to the defence of his title at Sea Island - managing just two birdies to finish the first day three shots off the lead.

American Mark Anderson (70) provided one of the highlights of the day, hitting a hole in one at the par-three third.