An Australia national rugby league representative wing, he played for the Sydney City Roosters and the St. George Dragons before they formed a joint-venture with the Illawarra Steelers to form the St. George Illawarra Dragons, with whom he continued playing, becoming the National Rugby League's top try-scorer for three consecutive seasons from 1999 to 2001.
Blacklock was the top try scorer in the Australian National Rugby League competition for three consecutive seasons whilst playing for St. George Illawarra between 1999 and 2001.
State selectors claimed that Blacklock's omission was necessary due to his small size and possible deficiencies in defence, because he would have to mark up against larger wingers such as Wendell Sailor or Lote Tuqiri.
Ironically the NSW Blues lost the series 2-1 and were humiliated in game 3 at AAMI Stadium by 40–14, where QLD wingers Lote Tuqiri and Wendell Sailor, as well as QLD centre Chris Walker ran riot over the selected NSW wingers Adam MacDougall and Jamie Ainscough, Ainscough coincidentally Blacklock's Dragons wing partner.
[citation needed] After a short stint playing rugby union with the New South Wales Waratahs, Blacklock returned to the St. George club during the latter half of the 2003 NRL season, where he again proved his worth by scoring 14 tries in 12 games.
Blacklock returned to help St. George Illawarra at the end of the year, which included scoring crucial tries in the club's round 25 come from behind win against Manly, as well as their narrow loss to Penrith during the first week of the finals.
After his retirement was announced, Blacklock came out and stated, "I'm disappointed I've had to call it a day, but I simply can't give the 100% I want to anymore because of injuries.
coach Peter Sharp added that "'Tingha' has enjoyed a marvellous career, he has achieved some things in rugby league that most people can only dream about.