A nightmare start saw the nervous 35-year-old from Northern Ireland overhauled by nearest rival Bryson DeChambeau at the top of the leaderboard in a three-shot swing in the opening two holes.
Then, after recovering to retake a three-shot lead with six holes left, McIlroy threatened to blow his chance yet again.
Those willing him to win wondered if he was fumbling another golden chance to finally land the prize which had long eluded him.
The rollercoaster nature of his triumph, secured eventually at the first play-off hole, was essentially a microcosm of a career which has provided exhilarating highs and devastating lows.
What his supporters had forgotten – understandably given the scar tissue they also had developed from his myriad near misses – was a very different McIlroy had emerged at Augusta National this week.
A mature McIlroy. A calmer McIlroy. A patient McIlroy.
Most importantly, perhaps, a McIlroy who has learned how to love himself again on the course after having his heart bitterly broken by the sport he adores.