The former world No. 1 looked back to his best after storming to victory at the Deutsche Bank Championship Monday to claim his first PGA Tour title for 16 months.
McIlroy started the final round at TPC Boston six shots adrift of overnight leader Paul Casey, but finished two clear of the Englishman at the top after holing seven birdies in a six-under-par 65 to reach 15-under 269.
And with the bumper multimillion-dollar prize on offer to the winner of the FedEx Cup, McIlroy is relishing the opportunity to make a late charge for top spot -- as well as leading Europe to glory in the upcoming Ryder Cup.
"I still need to keep going with it, it's definitely not the finished article, but it's a big step in the right direction," he told reporters after claiming the $1.53 million first prize to take his PGA Tour season earnings to $4.2 million.
"I'm excited with how my game is and what I've found this week, and hopefully I can keep it going for the next couple of tournaments, but ultimately into the Ryder Cup and trying to get a fourth one of those."
Ahead of the tournament, the Northern Irishman changed his putter and brought in a new putting coach after struggling on the greens this year.
"I knew my game was in good shape," the 27-year-old said. "I just needed to do something with the putting. I found something. I still need to keep going with it. It's definitely not the finished article, but it's a big step in the right direction."
This was McIlroy's first tournament triumph since winning the Irish Open in May and his first PGA title since May 2015, and lifted him to No. 3 in the world rankings.
The four-time major winner will rise 34 places in the FedEx Cup standings after this latest victory and will join the leading 70 players in the race at the BMW Championship next week.
Meanwhile, world No. 1 Jason Day finished in a group of six players tied for 15th. The Australian was told after Friday's opening round that his wife and children had been involved in a car crash, but decided not to pull out after they were cleared of serious injury.
The final event of the FedEx Cup takes place at the Tour Championship between September 22-25 -- just five days before the Ryder Cup between the US and Europe starts at Hazeltine.