England's Tommy Fleetwood carried on where he left off on Friday when the Alfred Dunhill Links Championship resumed.
Fleetwood shared the overnight lead with Northern Ireland's Michael Hoey on 12 under par, but birdied his opening hole at Carnoustie to move clear at the top of the leaderboard.
Hoey was also playing Carnoustie but had started on the tenth and a par there meant he was now in a three-way tie for second with Austria's Markus Brier and former Open Champion Louis Oosthuizen.
Oosthuizen was playing St Andrews, where he lifted the Claret Jug last year, and had opened with three pars and a birdie at the fourth, while Brier was two under for his first eight holes of the day at Carnoustie.
Fleetwood is seeking his second win in three weeks after victory in the Kazakhstan Open on September 11, with the first prize of €64,000 taking him top of the Challenge Tour rankings and securing his place on The European Tour for 2012.
But the 20 year old from Southport can pocket almost ten times that amount on Sunday, with victory worth €588,148 to the former Walker Cup player.
Despite the sunshine of the first two days giving way to damp, overcast conditions, low scoring was still the order of the day and Fleetwood soon found himself overtaken.
Oosthuizen picked up shots at the sixth and seventh at St Andrews to move to 14 under par, but Hoey birdied the 11th and 12th at Carnoustie and then eagled the 14th to jump to 16 under.
Former US Open Champion Graeme McDowell had also carded an eagle, holing out from 100 yards on the third at St Andrews to lie 13 under.
Play was then suspended at Kingsbarns due to fog.