"I got what I came for, and that was to win The Race to Dubai and do the double and create history."
Having captured the World Golf Championship –Accenture Match Play title in Arizona in February, he added The European Tour’s flagship BMW PGA Championship at Wentworth, beating Lee Westwood in a play-off and becoming World Number One in the process.
The 34 year old Englishman added a third title at the Barclays Scottish Open before winning the Children’s’ Miracle Network Classic at Disneyland to secure the US PGA Tour money list crown.
Coming as it did little more than a month since his father died suddenly, Donald did well to hold himself together over the closing few holes knowing what he had achieved.
He even birdied the last three holes for a second successive 66 and took third place in the tournament, one behind Scot Paul Lawrie and three behind Spain's Alvaro Quiros, who eagled the 18th for a notable double of his own after taking the Omega Dubai Desert Classic in February.
Only when he was being interviewed afterwards did the tears well up in Donald's eyes as he was asked what his father would have thought and done.
"He would have been very proud and he would just give me a big hug," he said.
"My father hopped into my head quite a few times (over the closing stretch).
"I didn't really look at a leaderboard until the 13th, but didn't see Rory's name and so knew it was mine."
McIlroy, who finished with another 71, has pulled out of this week's event in Thailand and on doctor's advice will stay in Dubai for a few days' rest before flying home.
He has been suffering from a virus and was even told it might be Dengue fever, so is looking forward to putting his clubs away until just before the Abu Dhabi Championship - Tiger Woods as well as Donald will be there too - on January 20-23.
"I think this week was one too many," he said, referring to a hectic recent schedule that has seen him make three trips to Asia and one to Bermuda.
"But Luke deserves it. Basically every time he's teed it up he's had a chance or he's finished in the top five or top ten.
"Mentally you have to be so good just to keep grinding out the scores when you need to.
"But I've made great progress this year - with my game, with my results, with everything.
"I feel like I'm swinging the club as good as I ever have and I feel like my body is as strong as it's ever been.
"I've won my first Major (by eight shots with a record score and at a younger age than any US Open Champion since Bobby Jones in 1933) and my goals are just to win tournaments and try to become a multiple Major Champion."