The 32-year-old landed his third success in the event - the first time he’s achieved that feat in his career - after seeing a recent link up with experienced English coach Pete Cowen pay dividends on the last day at the Charlotte venue.
A closing 68, which contained four birdies before a solitary dropped shot at the last, saw him finish on 10-under-par, winning by a shot from Mexican Abraham Ancer (66).
It had been 553 days since McIlroy won the WGC-HSBC Champions in China and he went into this tournament sitting 15th in the world rankings - his lowest position since 2009.
The triumph lifted the 32-year-old to seventh and, in contrast to being bereft of confidence before a missed cut in last month’s Masters, his tail is now well and truly up heading into next week’s US PGA Championship at Kiawah Island.
“This victory’s very important going into Kiawah,” admitted McIlroy, who won the same event there in 2012 by eight shots. “It’s certainly great timing.
“This is obviously a huge confidence boost going in there knowing that my game is closer than it has been. I’ll be able to poke holes in everything that I did today, it’s certainly far from perfect, but this one is validation that I’m on the right track.
“But it’s just the start. There’s so much more I want to achieve and so much more I want to do in the game. Hopefully history repeats itself and I can get a lot of confidence from this and go forward.”
The four-time major champion had landed his first Quail Hollow win when he opened his PGA Tour title account in 2010 before adding a second success five years later. This latest victory was sweet for more than one reason.
“I didn't even think I was going to tee off in this tournament Wednesday night,” he revealed after his first win since becoming a dad last year. “Then, even if I had had a morning tee time on Thursday, I probably would have pulled out because I hurt my neck on Wednesday afternoon and couldn't make a backswing.
“I had done a really good practice session on the range. I hit a 3-iron, flushed it and I turned back to talk to Harry (Diamond, his caddie) and as I turned, my left side of my neck just completely locked up and I couldn't move it.
“It was really, really strange. So I stopped what I was doing and I went and got some treatment. I iced it all of Wednesday afternoon, Wednesday night. I woke up Thursday, didn't have much movement.
“Was trying to make a backswing and could only maybe take it half the way back before it started to catch. If I had been playing Thursday morning, I probably would have pulled out, but I had enough time to get treatment Thursday morning, get it loosened up. It was still bothering me on Thursday afternoon.
“It then progressively got a little bit better as the week went on. It's just amazing how these little things, they all add up. It's so cool to be able to win here again, see some of the hard work that I've put in over the past couple of months finally start to pay off.”
Two shots ahead playing the last, McIlroy took a 3-wood off the tee only to pull it and, though his ball was fortunate not to end up in the creek that runs up the left side of the fairway, it had nestled down in a nasty spot.
McIlroy’s instant thought was to just get it on to the fairway, but that could have led to more trouble and, following Diamond’s intervention, he eventually took a penalty drop and safely found the green with his third to leave him with two putts to get the job done.
“Harry was awesome out there today, especially that decision on the last,” admitted McIlroy of his fellow Northern Irishman, who, unfairly, has often come in for criticism during their time together.
“I was ready to get in there and try to play that with a lob wedge and he was sort of like, ‘let's take a step back, let's think about this, where's the best place you're hitting your third from’. So he sort of calmed me down and slowed me down a little bit and said, ‘pal, let's just think about this a little bit’.
“Ultimately, we made the right decision and I dropped instead of trying to play that shot out of the hazard. Hit a great third shot onto the green and was able to two-putt from there.
“I think this is Harry and I's sixth win together and it's probably been our best one. Harry's been there every step of the way, the sort of tough parts that I've sort of had to endure over the last few months, and it's nice to come through all that with him and to get into the winner's circle again.”
It probably wasn’t a coincidence that happened in an event that seemed to have the most fans since golf welcomed crowds back in the Covid-19 world.
“I need this,” he admitted. “I feed off the energy so much. And I'm excited going forward now that we get to play in front of crowds like that. It was just an awesome experience to feel that again over the weekend.”
Russell Knox, the sole Scot in the field, signed off with a 72 to finish joint-18th on one-under.