The Rovers were equally successful under rugby rules, and such was their gathering reputation by January 1870, they had sufficient membership to enable the club to play two matches every Saturday, one under each code.

The first ever FA Cup goal was scored by Clapham Rovers' Jarvis Kenrick, in a 3–0 victory over Upton Park on 11 November 1871.

Their team in the 1880 FA Cup Final was: Lloyd-Jones (the youngest player in the side) scored the only goal of the game.

Additionally, Crampton and Walker were well-regarded forwards and Clapham was known to have "the strongest combination of the time behind the scrummage".

[6] On 26 January 1871, 32 members representing twenty-one London and suburban football clubs that followed Rugby School rules (Wasps were invited but failed to attend) assembled at the Pall Mall Restaurant in Regent Street.

A president, a secretary and treasurer, and a committee of thirteen were elected, to whom was entrusted the drawing-up of the laws of the game upon the basis of the code in use at Rugby School.

[8] The club played in cerise and French grey halves; Louis Birkett suggested the combination, having been taken by them on a dress worn by one of his sisters.