Coxon made his first grade debut for Souths against Cumberland in Round 2 1908 at the Royal Agricultural Society Grounds.
Coxon played a hooker as Souths claimed their first premiership winning 14-12 at the Royal Agricultural Society Grounds in front of 4000 spectators.
In 1909, Coxon played 11 times for the club as Souths claimed their second premiership in a row against Balmain in controversial circumstances.
Balmain were seemingly aggrieved at the demotion of importance of the Final, and asked the NSWRL to ensure it was played on a separate day.
On the day of the Final the Balmain players arrived outside the ground in the early afternoon, well before the scheduled kick-off time of 2 o’clock.