[6] He won the British and Commonwealth middleweight titles on 8 September 1970 at Wembley Stadium in London, stopping Mark Rowe at the end of the fourth round due to a cut.
After his original court hearing was adjourned after he arrived late, he was allowed to travel to Australia in January 1971 to defend his Commonwealth title against Tony Mundine, the fight ending in a draw.
[15] Sterling lost the Commonwealth title in April 1972, Tony Mundine stopping him in the fifteenth and final round in Brisbane.
[citation needed] Sterling made successful defences of his British title against Phil Matthews in September 1972,[16] Don McMillan in January 1973, and Rowe in April 1973, to win the Lonsdale Belt outright.
[citation needed] Sterling lost the British title in his fourth defence, Kevin Finnegan taking a points decision in February 1974.
When Finnegan vacated, he took the chance to win it back, stopping reigning light-middleweight champion Maurice Hope in the eighth round in June 1975.