The Englishman has handled the vicissitudes of golf like a consummate professional and is coming out of the slump that occurred after he was on top of the world in 2011, becoming the first man to win both the European and PGA tour moneylists.
His precision golf on Friday earned him nine birdies, six of them on the front nine he has always found harder, and he did not drop a shot as he recorded the best round at the Nedbank Golf Challenge since Lee Westwood’s 62 in the third round on his way to the 2011 title.
Overnight leader Ross Fisher was still strongly in contention on eight-under-par after a battling 70, while Marcel Siem went backwards with a level-par 72 that left him on four-under. South African fans, however, will be shedding a tear for the other member of the final three-ball, George Coetzee, who plummeted down the leaderboard to a tie for 11th after an error-strewn 74.
Stephen Gallacher roared to five-under-par with an eagle on the par-five 10th, but the Scotsman then disappeared down the Pilanesberg glens as he bogeyed 11 and 18 and double-bogeyed the 17th to finish on one-under-par.
It was left to Frenchman Alexander Levy, with a solid two-under-par 70, to claim third place behind Donald and Fisher on six-under, while another Englishman, Danny Willett, sowed some destruction on the back nine with three successive birdies from the 14th to jump to five-under overall.
There was an air of confidence about Charl Schwartzel’s game on the back nine as he picked up four birdies, but he tumbled down into a share of sixth after a double-bogey on the last hole left him on three-under with four other golfers.
Tommy Fleetwood fired a five-under-par 67 to also climb to three-under, while Tim Clark dropped three shots on the back nine to fall back to the same number, alongside American Brendon Todd and Thailand’s Thongchai Jaidee.
Fleetwood was the first golfer to eagle the infamous par-five 14th this year and he also finished strongly with birdies on the 15th and last hole.
Fisher, Siem and Coetzee all conspired to bogey the 14th to end their chances of catching Donald.
A poor tee shot on the par-three 12th hole cost Fisher the lead as the second round of the Nedbank Golf Challenge entered the back nine at the Gary Player Country Club.
Fisher had just overtaken fellow Englishman Donald with a stunning eagle-birdie combo at the 10th and 11th holes, but it all ended in tears on the 12th when he found the bushes way right off the tee and had to take a drop. He then chipped short of the green and chipped and putted for a double-bogey to drop back to nine-under-par.
Another wayward tee shot on the 14th forced him to take another drop as he bled another shot.
If the 36-year-old Donald – he turns 37 on Sunday – can win the Nedbank Golf Challenge it would be a tremendous coup for the former world number one whose loss of form since 2011 has been dramatic. Donald has not won a tournament since November 2013 and missed out on the European Ryder Cup team this year.
Levy was not far off the pace as he claimed three successive birdies after the turn to leap to seven-under, just three shots behind, but he parred the next five holes before dropping a shot at the 18th.
Birdies on the third and fourth holes lifted Fisher to eight-under-par, but Donald had already embarked on a dazzling run of five birdies in seven holes to jump to six-under.
Fisher was eight feet from the hole but on the fringe on the par-four third hole, but managed to sink the birdie putt to get his round going.
A top-class tee shot on the 195-metre par-three fourth set up another birdie as he finished just four feet from the hole.
Donald was putting together a superb round as he started with a pair of birdies and then also picked up shots at the par-three fourth and the par-four sixth.
A brilliant approach shot to 10 feet on the par-five second hole set up an eagle for Siem, the German recovering quickly from a three-putt bogey at the first hole. Two more birdies followed on the sixth and seventh holes, but he dropped another stroke on eight and bogeyed 14 and 15 as well.
Coetzee rolled in a birdie putt on the first hole but found himself scrambling for pars on the next three holes, and then his luck ran out with consecutive bogeys on five and six, plus another three dropped shots after the turn.
Gallacher was the other golfer to get on a roll, starting his round with two birdies and then birdieing three in a row from the fourth. He also eagled the 10th.
Jamie Donaldson will take no further part in the Nedbank Golf Challenge after withdrawing shortly before the start of the second round due to severe migraines.
The Welshman is apparently badly ill and was unable to join Mikko Ilonen and Marc Warren in the second group off the tee at 10.21am.
Donaldson shot a 74 in the first round to lie in a tie for 22nd place.