Jarrod Lyle has died at the age of 36, his family have confirmed.
Lyle passed away on Wednesday having entered palliative care last week, after which close friend Robert Allenby paid a touching tribute, writing: "We met because I was his hero. He has been mine ever since."
Having overcome acute myeloid leukaemia in both 1998 and 2012, forging a career in professional golf in-between, Lyle confirmed that the disease had returned for a third time last year.
"It breaks my heart to tell everyone that Jarrod is no longer with us," Lyle's wife Briony said in a statement released by Golf Australia. "He passed away peacefully at 8.20pm last night, having spent his final week in Torquay among his family and close friends."
"He asked that I provide a simple message: `Thanks for your support, it meant the world. My time was short, but if I've helped people think and act on behalf of those families who suffer through cancer, hopefully it wasn't wasted.'"
A father of two young girls and a popular member of the PGA Tour, Lyle's death casts a shadow over the season's final major, the PGA Championship, which begins on Thursday.
Defending champion Justin Thomas wrote on Twitter: "We lost a great one today. RIP, Jarrod. We will all be thinking about him and his family this week."
Earlier this week, Japanese golfer Hideki Matsuyama donated $50,000 to Lyle's family and Bryson DeChambeau gave the $25,000 charity prize he won at a pre-tournament long-drive contest to the cause.
Several other players, including Spain's Jon Rahm, have contributed and Tripp Isenhour's Go Fund Me page had received over $120,000 on Thursday morning.
Tributes were also flooding in, with Greg Chalmers describing Lyle as "a wonderful father, friend and golfer" who was "quick with a joke".