Jimmy Mullen admitted he was beginning to consider the possibility of winning the Alfred Dunhill Links Championship on his professional debut after maintaining a share of the lead.
Mullen added a 69 at St Andrews to his opening 64 at Kingsbarns to finish 11 under par alongside fellow Englishman Anthony Wall, with Walker Cup team-mate Paul Dunne, Ryder Cup star Jamie Donaldson, Denmark's Thorbjorn Olesen and American Chris Stroud a shot behind.
The 21-year-old from Devon joined the paid ranks after contributing four points to September's record victory over the United States at Royal Lytham, becoming the first Great Britain and Ireland player to compile a perfect 4-0 record since Paul Casey and Luke Donald in 1999.
"I don't really know what my expectations were to be honest," said Mullen, who carded five birdies and two bogeys on the Old Course, one of three venues used for the pro-am event.
"I'm just out there trying to enjoy it and learn really, and to be top of the leaderboard I can't really explain it. It's a different experience but I guess I'll just have to learn as I go along.
"The hardest bit for me is you watch the players growing up, from when I was a junior, and just realising that you're playing against them now and seeing them on the range. I'm still a bit like, 'There's (Martin) Kaymer and other people like that."'
Asked if he had thought about lifting the trophy - and winning the first prize of £525,000 on Sunday - Mullen added: "Yeah, it's impossible not to. Every time there's a scoreboard, I'm looking to see if my name is up there.
"It's impossible not to think about it, but I've got to just try and take care of tomorrow (at Carnoustie) and see what happens on Sunday."
Dunne is also making his professional debut and carded a 70 at St Andrews, where he shared the lead in the Open Championship after 54 holes before finishing in a tie for 30th.
That proved an inspiration for Mullen, who added: "I played with him the week before in the European Championships and managed to beat him on the 20th hole and the next week he's leading the Open after three rounds. Even though he was the one playing, it was a big confidence booster for myself."
Having played St Andrews and Carnoustie numerous times in his amateur career, Dunne admitted this week's event was an ideal way to start his professional career.
"There's a comfort level of playing on links courses and once you get out there it does not matter if you are an amateur or a pro," the 22-year-old from Greystones said. "There is still a golf ball sitting in front of you that needs to be hit.
"I'm really not thinking about the money. The money will take care of itself. If I keep playing good golf I won't have to worry about money. It would be nice to get a payday at the end of the week, but we won't find that out until Sunday evening."
The lowest rounds of the day came at Kingsbarns, with Bradley Dredge and Kiradech Aphibarnrat both shooting 63 to finish eight and six under respectively.
That represented an improvement of 10 shots on his opening round at Carnoustie for 42-year-old Welshman Dredge, who was baffled by the difference in scores.
"I've been playing golf a long time and haven't got a clue any more," said Dredge, who carded two eagles and five birdies in a flawless round.
"It was a bit of a tougher course yesterday and nothing went in. I got off to a slow start and then started playing nicely and just kept parring holes and not really doing anything.
"You come to today and I was three under after three, I hit some good shots and got off to a really good start and just kept going from there. And when I did get in trouble on two occasions, I made good par saves."
Defending champion Oliver Wilson, who was 792nd in the world when he won his first European Tour title 12 months ago, could only card a second consecutive 74 to lie four over par.
