Homburg next faced Guido Rinaldi, who lost a fifteen round decision to Archie Moore for the world Light Heavyweight title, three times in 1969, beating him in their first fight by a fifth round knockout, losing a ten round decision and winning their third clash, by an eighth round knockout. The latter would turn to be his last victory. Homburg went on boxing, but he lost his next four fights, including defeats at the hands of Oscar Bonavena and Jürgen Blin. On 11 December 1970 he held his last fight, losing by a ten round decision to Rüdiger Schmidtke in Cologne. Homburg retired from boxing with a record of 29 wins, 11 losses and 6 draws in 46 bouts, with 24 wins coming by knockout