Dubai - Mike Lorenzo-Vera fired a second-round 69 to widen his lead to three strokes at the half-way stage of the DP World Tour Championship on Friday.
But he was left lamenting a triple-putt bogey on the final hole that denied him the chance to rewrite the record books.
The Frenchman's 12-under par 132 matched the lowest 36-hole score in the 11-year history of the European Tour's season-ending championship.
England's Tommy Fleetwood and Spain's Jon Rahm, two players who can overtake current Race to Dubai leader Bernd Wiesberger and become the European number one, were tied for second at nine-under par 135.
Fleetwood, looking for a second straight win in two weeks after his Nedbank Challenge triumph, shot a 68, while Rahm eagled the 18th hole in his 69.
Wiesberger was nine shots behind the leader at three-under after a 71. If the results stand as of Sunday, Fleetwood will be crowned the Race to Dubai champion for the second time.
World number two McIlroy, who could do no wrong in his opening-round 64, struggled throughout the day and came home in 74 to slip to tied fifth place at 138.
England's Tom Lewis (70) was in fourth position at 137.
At one stage, Lorenzo-Vera, who led overnight by one stroke, had moved to five-under par and enjoyed a six-shot advantage. But he dropped a shot on the 15th and then came unstuck on the last hole.
"I think a three-shot lead is much better than being three behind," said the Frenchman, who is yet to win on the European Tour in 277 starts.
The 34-year-old was candid enough to admit that the $3 million winner's cheque, the biggest in the history of professional golf, was on his mind.
"Last night, I just sat down and tried to forget about it, but I could not. So I just embraced it. I went online and tried to find out ways I could spend it. I have already looked at some cars that I'd want to buy if I win."
Fleetwood made three bogeys on a day when the swirling wind in the afternoon posed problems but seven birdies ensured a round of 68.
"It was a good day. Played really well and stayed very patient," he said.
"It wasn't easy today. The wind really picked up. I think anything under par would have been really solid, so 4-under... I'm happy."
As for his position in the race to become the European No 1, the 28-year-old from Southport added: "There's a lot of different scenarios and players in the mix," he said.
"You have to be more internally focused just stay in your bubble. It will just be a great challenge going into the weekend trying to do that."
Rahm was two-over after eight holes but finished strongly on three-under.
"I felt odd all day. I missed quite a few short putts early on," said the world number five.
In the battle for the Rookie of the Year title, Scotland's Robert MacIntyre seemed to be opening a significant gap over the USA's Kurt Kitayama, but a double bogey on the 17th hole ensured they were separated by just one shot.
MacIntyre, ranked 11th in the Race to Dubai, shot a 74 and was on 145 while, Kitayama, 12th in the race,added a 75 to his overnight 71.
Complete second-round scores on Friday in the $8 million DP World Tour Championship at the par-72 Earth course of Jumeirah Golf Estates:
132 - Mike Lorenzo-Vera (FRA) 63-69
135 - Tommy Fleetwood (ENG) 67-68, Jon Rahm (ESP) 66-69
137 - Tom Lewis (ENG) 67-70
138 - Christiaan Bezuidenhout (RSA) 71-67, Thomas Pieters (BEL) 70-68, Rory McIlroy (NIR) 64-74
139 - Marcus Kinhult (SWE) 68-71, Justin Rose (ENG) 69-70
140 - Louis Oosthuizen (RSA) 70-70, Adri Arnaus (ESP) 70-70, Thomas Detry (BEL) 69-71
141 - Shane Lowry (IRL) 73-68, Bernd Wiesberger (AUT) 70-71, Danny Willett (ENG) 69-72, Rafael Cabrera-Bello (ESP) 68-73
142 - Patrick Reed (USA) 74-68, Matthew Fitzpatrick (ENG) 71-71, Matthias Schwab (AUT) 69-73
143 - Lee Westwood (ENG) 73-70, Guido Migliozzi (ITA) 73-70, David Lipsky (USA) 72-71, Erik van Rooyen (RSA) 71-72, Jason Scrivener (AUS) 71-72, Richard Sterne (RSA) 71-72
144 - Aaron Rai (ENG) 75-69, Henrik Stenson (SWE) 74-70, Sergio Garcia (ESP) 71-73, Matt Wallace (ENG) 70-74, Benjamin Hebert (FRA) 70-74, Andy Sullivan (ENG) 70-74
145 - Joost Luiten (NED) 74-71, Jorge Campillo (ESP) 73-72, Robert MacIntyre (SCO) 71-74, Romain Langasque (FRA) 71-74, Francesco Molinari (ITA) 69-76
146 - Matthew Southgate (ENG) 75-71, Victor Perez (FRA) 73-73, Paul Casey (ENG) 73-73, Justin Harding (RSA) 73-73, Kurt Kitayama (USA) 71-75, Li Haotong (CHN) 69-77
147 - Joachim B Hansen (SWE) 74-73, Jordan Smith (ENG) 74-73
148 - Mikko Korhonen (FIN) 72-76, Paul Waring (ENG) 71-77
150 - Ian Poulter (ENG) 74-76
151 - Scott Hend (AUS) 76-75, Andrea Pavan (ITA) 77-74
152 - Tyrrell Hatton (ENG) 73-79