Green knocks out Jones Jr in Sydney

"I almost feel bad doing that," said Green, who has won 28 of his 31 career fights, including 25 by knockout.

"That almost most hurt me to do that to someone whom I aspire to look up to as a professional fighter inside and outside the ring."

The loss may also have cost the 40-year-old the chance of a lucrative fight with his old adversary Bernard Hopkins, who had agreed to a rematch next year on the condition Jones beat the Australian.

"We don't make excuses, it was a great performance by Danny," said Jones, whose record now stands at 54 wins and six losses from 60 fights.

(Reporting by Julian Linden; Editing by Miles Evans)