The 1877–78 Welsh Cup was the first season of the Welsh Cup. The cup was won by Wrexham who defeated Druids 1–0 in the final.
First round
Source: Welsh Football Data Archive
Replay
Source: Welsh Football Data Archive
Second replay
Source: Welsh Football Data Archive
Llanerchrugog received a bye to the next round
Believing that it was a Rugby Union competition Swansea RFC scratched to Aberystwyth when officials learned that it was one for football.
Second round
Source: Welsh Football Data Archive
Replay
Source: Welsh Football Data Archive
Third round
Source: Welsh Football Data Archive
Replay
Source: Welsh Football Data Archive
Second replay
Source: Welsh Football Data Archive
Bangor receive bye to next round
Semi-final
Source: Welsh Football Data Archive
Replay
Source: Welsh Football Data Archive
Wrexham receive bye to next round
Final
The final of the inaugural Welsh Cup tournament was played at Acton Park, Wrexham on 30 March 1878 between Wrexham and Druids of Ruabon. The match was a cliffhanger, with no score until the Wrexham forwards charged the Druids' defenders to take the ball over the line to win the game in the final minute, with James Davies being credited with the goal.
References
The History of the Welsh Cup 1877-1993 by Ian Garland (1991) Welsh Football Data Archive