Tyrrell Hatton picked up an early birdie on the Old Course at St Andrews as his quest to make European Tour history reached the home straight at the Alfred Dunhill Links Championship.
After winning this event in 2016 and 2017, the Englishman is seeking to become the first player in 11 years to win the same European Tour event in three consecutive seasons.
Tiger Woods was the last player to do it between 2005 and 2007 when he completed a hat-trick of both the WGC-Championship and the WGC-Invitational.
Ernie Els was the last man to do it in a regular event as he won the Heineken Classic every year between 2002 and 2004, while Nick Faldo is the only Englishman to have previously achieved the feat at the Irish Open between 1991 and 1993.
Hatton started the day with a one-shot lead and his birdie on the third moved him to 15 under, two ahead of Australian Marcus Fraser.
Countryman Tommy Fleetwood and Scot Stephen Gallacher were then at 12 under, a shot clear of Dane Lucas Bjerregaard and American Brooks Koepka.
Every player went off between 08:30 and 08:40 in a shotgun start due to high winds expected later, with the leading two groups overnight going off the first.
Fleetwood made the first move with a birdie on the second, while Bjerregarrd birdied his first hole after starting on the 18th to get within three.
He was soon joined there by Koepka who - after starting on the 17th - birdied the 18th and first.
Playing partners Hatton and Gallacher then both birdied the third as Fraser started his round with three pars.
Andrea Pavan and Brandon Stone were at ten under, a shot clear of Tapio Pulkkanen.