The 27-year-old carded seven birdies on his way to a six under par opening round of 66.
Playing at Kingsbarns Golf Links, Mansell picked up shots on the first, third, fourth, ninth and 10th before his only bogey of the day at the 11th.
But birdies on the 16th and 18th rounded off a fine day and left him tied in 11th place.
Fellow Staffordshire golfer Robert Rock endured a testing day at Carnoustie where he carded a two over par 74.
Frenchman Romain Langasque topped the overnight leaderboard following a course record-equalling 61 at the Old Course at St Andrews.
Langasque recovered from an early bogey with two eagles and eight birdies to reach 11 under par and tie Ross Fisher’s record at the historic venue.
Langasque said the achievement will live long in his memory.
“I’m so happy, the last three holes were really fun and I made long putts,” he said.
“It’s amazing. I didn’t realise that I have the course record here now and I think it’s something I will remember for the rest of my life.”
Countryman Frederic Lacroix was Langasque’s nearest challenger on 10 under after firing a spotless 62 over at Kingsbarns, with another Frenchman – Antoine Rozner – tied for third alongside Dane Niklas Norgaard Moller on nine under.
England’s Daniel Gavins was the leading British player on seven under after his bogey-free 65 at the Old Course.
World number two Rory McIlroy began the week with a 68 at Carnoustie, as did Francesco Molinari on his return to the venue where he won the 2018 Open Championship.
As well as topping the leaderboard, Langasque and partner Roy Ryu co-lead the team competition on 14 under par alongside Andrea Pavan and Kieran McManus.
Due to the weather forecast, Friday’s second round will have a shotgun start at 8.30am on all three courses, with leader Langasque tackling Carnoustie on day two.