JP and Rors have benefited greatly after rocky start to their partnership
Rory McIlroy has employed only two caddies in his professional career - Gordon Faulkner and JP Fitzgerald.
Faulkner, who caddied at Queensway GC in Surrey, was recommended to McIlroy by Darren Clarke. He carried McIlroy's bag in the 2007 Walker Cup after which the Holywood GC member turned professional, but their relationship lasted less than a year.
By the summer of 2008, the fledgling professional found himself struggling to adjust to life on the road. His then manager, Chubby Chandler, has been credited with suggesting that Fitzgerald come on board.
The former single figure amateur had played in the 1987 and 1992 Irish Close Championship, reaching the final both years.
Fitzgerald attended East Tennessee State university on scholarship, and when he returned to Ireland was offered his first caddie's job with Paul McGinley in 1995.
The County Louth GC member worked with McGinley until 2003, and after that had spells with Clarke, Greg Owen and Ernie Els before he came on board with the McIlroy roadshow.
Their first event together was in the 2008 SAS Masters in August. Missed cut. Next event, the KLM Open. Missed cut. Third event, Johnnie Walker Championship. Missed cut. Not an auspicious beginning, but finally McIlroy had a breakthrough and got beaten in a play-off for the Omega Masters in Switzerland.
McIlroy was 210th in the world rankings, but by the end of 2008, the Ulsterman was 40th.
They earned their first victory in February 2009 at the Dubai Desert Classic. The golfer was just 19 and the victory proved to be a launch pad.
Since then they have gone on to win 20 tournaments, including four Majors, and seen McIlroy reach World No.1.
Through it all, Fitzgerald remained the 'quiet man' who has shunned publicity. The man from Castleknock in Dublin is known for his brand of dry humour but when on duty, preferred to stay in the background.
Fitzgerald never complained about criticism that came his way from commentator Jay Townsend at the 2011 Irish Open in Killarney, or other gripes concerning his stewardship.
Townsend, a former pro, had a go at the caddie's performance on social media, saying: "JP (Fitzgerald) allowed some SHOCKING course management." McIlroy blasted back, also on Twitter: "You're a commentator and a failed golfer, your opinion means nothing."
That led to a right royal row and calls for McIlroy to apologise.
"He's been having a go at JP every now and again since then and this was the first time I've responded," said McIlroy.
Through all the ups and downs over the last nine years, overall the two men prospered.
Financially, Fitzgerald hit the jackpot in his chosen career.
McIlroy's total prize money from the PGA Tour and European Tour totals around £58m, and the caddie's gross earnings are estimated to be around £6m.