The tournament is being contested using the modified Stableford scoring system that awards five points for an eagle, two points for birdie and zero points for par. One point is deducted for a bogey and three are taken away for a double-bogey or worse.
The first round was delayed due to rain that earlier in the week looked like it might postpone part of the tournament.
Frenchman Raphael Jacquelin is alone in second with 15 points, followed by Carl Pettersson, who had 13 points in round 1.
Lomas dropped his only stroke with a bogey at his 3rd hole, but he rebounded with four birdies on his front nine. He chipped in for eagle at his 8th, the par-5 17th at the Lakes Course, which gave him five points and a push to the top of the leaderboard.
He added four more birdies on the back to reach his 20-point total.
Lomas believes that the change in scoring style, coupled with the receptive greens that slowed down with the rain, could lead to a successful week.
'I am not scared of hitting driver at all on some of these holes. Being more positive, I suppose, being more aggressive on the course and with the putter as well. The greens were a lot slower than last week.' Lomas said.
Euan Walters and David Lynn share fourth-place with 12 points.
Patrik Sjoland, Marcus Norgren, Andre Stolz, David Smail, Scott Laycock and Jean-Francois Remesy are tied for sixth with 11 points.
Aaron Baddeley, who won the Greg Norman Holden International at this same venue last year in a playoff over Sergio Garcia, struggled on Thursday with four bogeys and three birdies. He shares 94th with former Georgia Tech star Bryce Molder and others with two points.
Full-field scores from the ANZ Championship