The 32-year-old from Johannesburg looked to have the title safely wrapped up when he stood seven under and led by two strokes coming to the par three 16th. That's where his troubles began. He ran up a double bogey to drop back to six under for the championship and by that point he had been overtaken by the Frenchman Thomas Levet and two Australians, Stuart Appleby and Steve Elkington.
It meant Els needed to birdie the long 17th and par the 18th to stay in the race. He did so with commendable composure and so paved the way for the longest play-off in Open history. Those to previously prevail in extra time were Mark Calvecchia at Troon in 1989; John Daly, St Andrews, 1995; Mark O'Meara at Birkdale in 98 and the most memorable of all, Paul Lawrie at Carnoustie the following year. They all prevailed within the first four holes.
Australians Elkington, who had to pre-qualify to play in the championship, and Appleby, dropped out after the regulation four holes leaving Els and Levet to fight it out in sudden death. Levet found sand off the tee and was never doing better than five.
However, Els dragged his approach into a greenside bunker and had to play his recovery with one leg in the trap. But he conjured up a superb recovery to less than a yard and tapped in for his third major title coming on top of a couple of US Opens in 1994 and 97. He was immediately embraced by his wife Liezl and father Neels as emotions ran high.
All the time, Padraig Harrington looked on from the players' lounge ruing what might have been. He had played aggressively, sensibly and well throughout the day until he stood on the 18th tee on six under par and believing that he needed a birdie to have any chance of staying in contention.
"So I abandoned my game plan of going with a three or one iron and instead opted for the driver in the hope of putting myself within eight iron reach of the flag", he explained as the play off quarter disappeared down the fairway and into the delightful late evening Muirfield sunshine.
"I wasn't to know that Ernie, who was eight under at the time, would take double at the 16th, you don't expect something like that from such a great player. Even in hindsight, though, I would do the same thing, it was the right decision then and the right decision now".
Harrington had to settle for a share of 5th, his third top 10 finish in this year's majors and his fifth in all. He picked up a cheque for 140, 000. Des Smyth finished with a 73 for level par (the same mark as Tiger Woods, who yesterday bounced back from Saturday's 81 with a 65) and won 24,000. Darren Clarke was a stroke further back in a share of 37th and earned 16,916.
Not that it matters to a man of his means, Els departed richer by a record Open first prize of 750,000 and with his confidence, which had been fragile in recent times, restored having ended his five year drought without a major title. He shot rounds of 70, 66, 72 and 70 with the three runners-up Stuart Appleby, Thomas Levet and Steve Elkington picking up 286,666.
"I thought I had lost it with that double bogey at 16," Els said. ""I like to draw my irons but have been struggling with that shot of late. I had a similar chip at the 4th but tried a different approach this time and to be honest, I thinned it. I asked myself if this was the way I wanted to be remembered, losing another major I should have won. My caddy Ricky Roberts, an Englishman] calmed me down and told me to just make a good swing. I've been happy with the driver throughout the week and I nailed it. I had 247 yards to the hole and hit a beautiful three iron to twenty feet.
"Somehow, I pulled myself together and hit a few good shots. But I haven't a good record in play offs and wanted to win it in regulation time. When I left my putt on the 18th short, I was really down in the dumps. I went to the scorers tent and came out and met Liezl and Jos (Vanstiphout, the Belgian psychologist) who, ironically, also works with Levet] and he told me to concentrate and just remember the four holes I still had to play were the most important of my life."
In the end, it all worked out nicely for Els and so justice was served. It would have been an absolute shame had a great championship been won by a player who had come racing through the field by playing in the calm of Saturday morning rather than the storm of the afternoon. The South African battled his way through the very worst of the rain and wind and held his head when many most notably Woods were losing theirs and somehow eked out a 72. He is a very worthy champion.
"I was under unbelievable pressure out there," he said last night. "It would have been a very hard loss to take. You think of the Masters and of the guys who failed to win it when they should have. You can only take so much. Some people never recover. I've dreamed of winning this since I was eight-years-old and now I'm back on track".
Meanwhile, the consolation for Thomas Levet is that he emerged as the people's champion. He constantly waved to the massive galleries, urging them to cheer louder and louder, and even lifted Els in triumph at the conclusion of the play-off.
If his compatriot Jean Van de Velde will always be remembered for the manner of his play off defeat at Carnoustie three years ago, the style with which Levet accepted his lot will remain an endearing moment.
"I am very happy with today," he said with every justification. "I lost to a great player. He's very talented and that bunker shot at the end was special."