Justin Walters was full of emotion after topping the leaderboard on day one of the Dunhill Links.
The South African withdrew from the Porsche European Open earlier this month following the death of his father.
Walters, sitting 143rd on the Race to Dubai and in danger of losing his card, produced a putting masterclass with nine birdies and nine pars on the Old Course to move one shot clear with a round of 63.
He said: “I haven’t shot anything under 69 or 68 in a long time.
“To do it at St Andrews, and the emotions I’ve been through the last few months, is so special.
“I have been swinging really well all year from when I qualified for the US Open and I got to the Irish Open and tore my calf really badly. I struggled to get right for a while. I finally got over that and then I lost my dad.
“It was quite hard but I decided not to feel sorry for myself. I dusted myself off and came here. It has a healing quality.
“I was here (at St Andrews) with my dad when we lost Mum, and just thought I was back with him.”
Frenchman Victor Perez, who lives in Dundee, is tied second on eight under after a 64.
He said: “My girlfriend goes to dental school here. I’ve lived here for the last year and a half.
“Playing links golf all the time when I’m not in tournaments makes a big difference.
“I’m used to the bounce and the greens and it definitely played to my advantage.”
Aberdeen’s Richie Ramsay is the leading Scot after a seven-under 65 at Kingsbarns, with Inverness’ Russell Knox one shot further back after a 66 at the Old Course.
