Ireland’s Shane Lowry carded a four-under-par 68 at Wentworth to lie two shots off the pace set by Sweden's Johan Carlsson at the BMW PGA Championship.
The Offaly man bounced back from bogeys on eight and nine to post three consecutive birdies at the start of the back nine as he went on to card five birdies in total.
Paul Dunne is next best of the Irish contingent on one under.
Three-time major winner Padraig Harrington is one over, alongside 2011 Open champion Darren Clarke.
Damien McGrane is tow over and Neil O’Briain is 10 over.
Ernie Els showed admirable sportsmanship when he called a penalty on himself.
Els appeared to have chipped in for an eagle on the par-five 12th, but instantly realised he had not replaced his ball in the right place after checking to see if it was plugged.
The four-time major winner was therefore assessed a two-shot penalty (under Rule 20-7) and eventually signed for a one-under-par 71.
"I pulled my second shot a bit left and hit it into the bank of the bunker," Els explained. "I thought it was plugged, so I asked my guys (playing partners) if I could check it and they said, 'Yeah'.
"I put it back and I hit my chip shot and I just felt uncomfortable by the way the ball came out. The ball came out way too good so I felt I didn't quite probably put it exactly where I should have.
"Under the rules you try and put it back the way you think it should be, but I still felt uncomfortable with it, so we took a two-shot penalty. I know deep down the ball wasn't quite where it should be and I wouldn't be able to live with myself."
Els at least had reason to celebrate the verdict on his latest redesign of the West Course, which has met with universal approval from his fellow competitors.
"The greens are absolutely as pure as you can find," said the 47-year-old, who was visibly upset by criticism of his original redesign in 2010.
"Next week we'll be playing the Memorial (at Muirfield Village) and I think these greens are running just as good or better than the Memorial, or Augusta for that matter.
"We listened to some of the players' comments through the years since we started first changing and I think I feel we've got it right this time."
"We had the best of the conditions, not a breath of air, and the greens are so good this year," said Scotland's Scott Jamieson, who was in the first group out at 7am and carded a flawless 67.
"To be the first people on all 18 greens, they are just a great surface to putt on."
Jamieson's score was matched by Kiradech Aphibarnrat and Francesco Molinari, with Open champion Henrik Stenson and Ryder Cup star Thomas Pieters part of a nine-strong group on four under.
Pieters, who bogeyed the last after finding the water with his approach, was making his first start since finishing in a tie for fourth at the Masters, having opted to miss the Players Championship in favour of a family holiday.
"There's been some criticism on social media but that's my decision and if you're not happy with it that's your problem," said the Belgian, who won a record four points on his Ryder Cup debut at Hazeltine last year.
Stenson birdied four of his last eight holes after starting with 11 straight pars on just his second appearance in the event in the last seven years, while Lee Westwood carded a 70 on his 24th consecutive appearance.
Danny Willett, Justin Rose and defending champion Chris Wood all finished on level par, with Wood throwing his ball into the water on the 18th after a bogey six.
