UPDATE: FLAGS are flying at half-mast at the SCG and the cricket world is grieving for beloved commentator and player Tony Greig.
Greig died yesterday after suffering a cardiac arrest while fighting lung cancer.
Greig, 66, was diagnosed in October and was due to begin chemotherapy this week, Channel 9 sports director Steve Crawley said.
He was rushed to Sydney's St Vincent's Hospital by ambulance from his Vaucluse home at 11am. He was pronounced dead at 1.45pm.
Greig - a champion all-rounder who played 58 Tests for England, 14 as captain - had taken time off from his Channel 9 broadcasting duties to fight the cancer, but had maintained his famously optimistic outlook.
On Christmas Day he had posted on Twitter: "Merry Christmas and a happy, healthy and prosperous New Year to you all. Would love to be at Test but son Tom and I will be tuned in."
His wife Vivian said last night: "Our family wants to extend our gratitude for the support and condolences we have received, and ask for privacy at this very sad time."
As flags at the SCG were lowered to half-mast, his close friend David Gyngell led the tributes from around the world. The Channel 9 CEO said: "The network has lost part of its extensive cricketing DNA with his tragic passing.
"It is a deeply upsetting time for his family and for everyone associated with Tony at Nine, and indeed for many, many others who came to know and love the man."
James Packer described Greig as a "larger-than-life figure" who "played an absolutely pivotal role in the success of World Series Cricket, which changed the game forever for the better".
"Tony stood shoulder to shoulder with my father (Kerry) at times when it was not always fashionable.
"Together with the backing of other key players and supporters they forged a brave new age for both cricketers and spectators.
"For that alone, every fan is in Tony Greig's debt."
The charismatic South African-born cricketer became one of the masterminds of the World Series Cricket in 1977 - convincing many of his English teammates, as well as West Indian and Pakistani cricketers, to defect.
He quickly became a great mate of media mogul Kerry Packer and that friendship continued until Packer died on Boxing Day in 2005.
It also resulted in Greig being offered a "job for life" at Channel 9 as a respected cricket commentator.
Every summer he could be seen jamming his key into the cricket pitch and often enjoyed fiery discussions with his fellow commentators, in particular his dear friend and old sparring partner Bill Lawry, and Ian Chappell.
Richie Benaud had conveyed the sad news to Greig's fellow commentators.
Greig revealed his battle with cancer in The Sunday Telegraph in late October. He said: "I have had a few scrapes in my life and this is another one. Vivian (his wife) and I are going to put the boxing gloves on and fight this like we've never fought anything."
Ian Chappell said last night: "We knew the news was bad but I didn't realise it was going to be this sudden.
"He was such a fighter on the field, and he showed the same optimism away from the field as well.
"We had our run-ins on the cricket pitch, but he'd often come into the dressing rooms afterwards with a beer in his hand and we'd laugh about the silly things we said on the field.
"He was damn good company and always had a passion for the game."
Former Australian captain Steve Waugh said Greig had inspired him to play.
"As a young boy working the scoreboard at Bankstown Oval I eventually summoned up the courage to walk up to him and ask for his autograph as he sat waiting to bat next for Waverley," he said. "He was very gracious in his response and while it was only a brief exchange it certainly ignited my desire to one day be a professional cricketer."
Greig and Vivian had a daughter Beau, 12, and son Tom, 10. Greig also has two adult children, daughter Sam, 39, and son Mark, 37, from his first marriage.
Plans are under way to honour Greig at the Australia v Sri Lanka Test match beginning at the Sydney Cricket Ground on Thursday.
FACT FILE: TONY GREIG ON THE CRICKET PITCH
Highest score: 148
Bowling average: 32.20
Best bowling: 8-86
One Day Internationals: 22
Highest score: 48
Bowling average: 32.57
Best bowling: 4-45
Read more on the Herald Sun.