HUDDERSFIELD'S Chris Hanson leads the Yorkshire challenge in the Joburg Open being played over two courses at Royal Johannesburg & Kensington GC.
But Malton's Simon Dyson had the most eye-catching finish, eagling the par-5 18th on the East Course for a two-over-par 74.
Leeds's Daniel Gavins and Hull's Richard Finch, also playing the East Course, shot 77 and 78 respectively.
Woodsome Hall's Hanson was the sole Yorkshireman to make it beyond the cut at last week's BMW SA Open.
He dipped one below par on the West Course on Thursday with a 70, but might have expected a lower score given that it was the "best I've played tee to green in 12 months."
He added: "It was a really enjoyable performance, I just had a pretty cold putter, but that's something that an afternoon of practice has hopefully sorted."
Hanson, who has made the cut in two of his three events in his maiden season on the European Tour - he was just one shot adrift in the other - had two birdies on his outward nine that were counter-balanced by two bogeys.
Coming home, he had eight pars and a birdie at the 16th.
Dyson, a six-time Tour title winner who returned after a seven-month injury absence last week, had both an adventurous beginning and ending to his round.
Birdies at the first and third sandwiched a bogey at the second. He then carded a further six bogeys in his next 14 holes, and a birdie at the 16th, before his spectacular closing eagle.
Gavins, like Hanson, is a newcomer to Europe's top tier of tournament golf and missed the cut on his bow at the BMW SA Open after a promising opening round.
On Thursday, he repaired half of the damage inflicted by bogeys at holes three and five with a birdie at six.
He then gave away two further shots to par with a double bogey at the next, again partially off-setting the damage immediately with a birdie at eight.
On his inward nine he had three consecutive bogeys from the 11th and will hope to take advantage of playing the West Course on Friday, which Hanson indicated players believed to be the easier of the two as it is shorter in length. "But you still have to hole the putts," he said ruefully.
Finch, who was forced to retire last week after just seven holes of the BMW SA Open, his first event after regaining his card at the Tour's Qualifying School, shot a 78 on Thursday over the East Course.
He was three over after five holes, shed four more in a four-hole stretch on the back nine, but carded his only birdie of the day at the 17th.
Anthony Wall, David Howell and Mark Williams all shot 65 to lead on the West Course, South Africa's Justin Walters leading with the same score over the East Course.