IT HAS been nine years since Matt Damon played Jason Bourne on the big screen.
The Oscar winner revealed tonight it was director Paul Greengrass who lured him back to the action spy franchise.
Greengrass directed the two Bourne sequels, The Bourne Supremacy and The Bourne Ultimatum.
A fourth Bourne film was released in 2012 but starred Jeremy Renner in the lead role as another agent affected by the events of Damon's previous films.
"I always wanted to do it but I just couldn't do it without him," he said at the film's Australian premiere in Sydney tonight.
"Once he decided to do it that was it."
Attendees of tonight's premiere were the first in the world to see Damon in his highly-anticipated return to the franchise, based on Robert Ludlum's novels.
"You guys really are the first audience to see the movie," he said at Hoyts Cinemas at Moore Park.
"Australia's always been really great for us and the franchise. It's out-performed expectaions here always. This is it; if you guys don't like it..."
Damon also reflected on the physical role as a black ops agent suffering from amnesia, which he first played at the age of 29.
"When I did the first one I was 29 years old and I thought I was working out really hard," he laughed.
"Now I'm 45 and it was really hard (this time).
"To spend that much time in the gym is just weird unless you're a professional athlete, which I'm not. It took a lot of exercise and dieting, which is kind of a pain. Hopefully it was all for a good cause."
The new Bourne movie also took Damon back to Las Vegas where he filmed the popular Ocean's Eleven franchise.
"The funny thing is with Ocean's Eleven at the end of that movie we're all standing in front of that fountain at the Bellagio, this iconic fountain," he said.
"That's where we blow up about 150 cars in this movie, right out in front of the Bellagio."
Jason Bourne opens in cinemas on July 28.
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