In 1968 Hawthorne accepted a then record $30,000 contract to switch to the professional code and join the
St. George Dragons. He played fifty-six games for the Dragons from 1968 to 1971 at
Five-eighth before he joined
Eastern Suburbs for his final season in 1972. In 1969 he appeared as a guest player for
Auckland in a match against the
New Zealand national rugby league team to mark the
New Zealand Rugby League's diamond jubilee. Phil Hawthorne's international rugby league debut against Great Britain in Brisbane on 6 June 1970 alongside
John Brass saw them together become Australia's 32nd and 33rd dual code rugby internationals. He played all three Tests against Great Britain in 1970 and was captain in the 3rd Test with
Langlands and
Sattler injured and unavailable. He is named on the Australian Players Register as Kangaroo No. 441. Injury restricted Hawthorne's appearances in 1971. He left the club at the end of that year to join the
Eastern Suburbs Roosters but spent much of the 1972 season in reserve grade behind the competition's eventual player of the year, his former Wallaby teammate John Ballesty. He moved to
Coffs Harbour in 1973 and captain-coached Coffs Harbour to Group 2 premierships in 1973 and 1974. He was diagnosed with
leukaemia in 1991, and died in September 1994, at the age of 50. ==Notable statistics==