Sydney (AFP) - Matt Giteau has announced he is retiring aged 40 after a career in which he won 103 caps, but he may be remembered more for 'Giteau's Law' which was key to the Wallabies reaching the 2015 Rugby World Cup final.
Giteau was at the time enjoying a stellar spell with French club Toulon but with the national side's fortunes at a low ebb then-Australia head coach Michael Cheika argued they must change their ban on selecting players who played abroad.
Cheika succeeded in pushing through a change that covered players with 60 caps or more, so Giteau and his fellow Toulon team-mate Drew Mitchell made the World Cup squad.
Both played pivotal roles as Australia reached the final where they gave New Zealand a run for their money at Twickenham -- even though they lost Giteau inside half an hour to a head knock -- before the All Blacks prevailed 34-17 at Twickenham.
Giteau retired from Test rugby the following year but carried on playing at club level -- his last side was the now defunct American outfit LA Giltinis.
"It's been such an amazing experience (and) one that I will miss but I have milked this game and the contracts dry," Giteau wrote on social media.
"Half my life spent playing this great game professionally and traveling the world getting to do it."
Giteau -- who was also part of the Wallabies squad that lost to England in the 2003 World Cup final -- won three European Cups and a Top 14 title as part of a star-studded squad in a six-year spell at Toulon.
He thanked his family for following him round the globe.
"Special mention to my wife and kids who sacrifice so much for me to prepare and play for so long," he wrote.
"Moving countries, schools, and away from friends so that I could continue to play (and) chase my dreams.
"Huge thanks to my parents also, who have travelled the world to support me and the sacrifices they made for me to actually make a career out of this sport."
David Pocock, another of the standout players from the 2015 World Cup campaign, paid Giteau a handsome tribute on social media.
"Magician on the field and awesome teammate, husband and father off the field," said Pocock.
"One of the greats.Loved watching you play for the Wallabies while I was at school, then getting to play alongside you (and) then watching you from the couch still carving up after I'd retired," added the 34-year-old.