McIlroy went into the event with a new putter and a new putting coach in Phil Kenyon, the Englishman who is now involved with seven members of Europe's Ryder Cup team.
In July, he described his putting as "pathetic" after missing the cut at the UPGA Championship at Baltusrol, but in Boston he emerged top in putting average and birdies made.
Those figures suggest the changes he made worked as McIlroy, who also tweaked his grip before Saturday's third round, emerged with his third FedExCup playoff title and his first PGA Tour win for 16 months.
It was not just his putting that clicked, however. Several of his seven birdies came with the help of pinpoint bunker shots and the win was all the sweeter for coming on the back of a terrible start which saw him four over after the opening three holes.
McIlroy's personal triumph also represented a boost for Team Europe who need McIlroy at his fearsome best at Hazeltine between Sep. 27 and Oct. 2.
"I am really proud of myself for battling that first day, getting some momentum on Saturday and just going with that. It is nice to get that first win in the States this year," he said.
"Hopefully this is momentum I can bring on to the next couple of weeks and ultimately the Ryder Cup to hopefully help Team Europe win another one of those. I’m really excited going into the last part of the season."
The win puts McIlroy back in the top three in the world rankings and savouring the next FedEx playoff event, the BMW Championship which starts on Thursday at Crooked Stick.
Since that is a course where he won in 2012, he will feel confident he can do enough to stay in the top five of the FedEx standings for the final event and in touching distance of the $10 million (7 million pound) overall prize.
That would be a tidy sum to have in his back pocket before the start of the Ryder Cup the following week.
"One of the things I would like on my golf CV is to win the FedEx Cup," said McIlroy. "The next two tournaments are huge for me, to try and do that."
(Reporting by Neil Robinson; Editing by Alison Williams)
