Bowley, H.F. Blaine, G. Lane, A.A. Hadow, and H. Carlisle)[4] Under its new guise, the team played in the FA Cup competitions regularly in the late 1870s and 1880s.

"[5] In the fourth round, they defeated Upton Park 3–1, putting them into the semi-finals and needing only to beat the Royal Engineers to face the Wanderers (who had a bye) in the final.

However, they lost 2–1 in the semi-finals on 16 March 1878; the Harrovians took the lead, but, just before half-time, captain R. de C. Welch suffered an eye injury, which required him to go in goal for the remainder of the match, "weakening his side considerably"; the Sappers duly scored twice in the second half to go through.

[6] There were obviously no hard feelings between the sides, as the Sappers nominated the Old Harrovian half-back Beaumont Jarrett as its umpire for the final.

[7] The following season saw another cup run as the team beat Southill Park 8–0 in the first round[8] and Panthers 3–0 in the second, before losing 2–0 to Nottingham Forest in their third match.

The club did not appear in FA Cup again until 1885–86, first talking a walkover over St James, beating Old Foresters 2–1, but were then disqualified in their third round match against Swifts.