On 29 September 1971, Chelsea recorded their widest margin of victory, beating Jeunesse Hautcharage 13-0 in the second leg of their first-round meeting in the Cup Winners' Cup.
The tie was effectively over after the first leg, with Chelsea beating Hautcharage, an amateur side, 0-8 in Luxembourg. But the 27,621 people who turned up at Stamford Bridge for the second leg were treated to a match of historic proportions.
Striker Peter Osgood (pictured) started the scoring deluge, providing the opening goal in the fourth minute, then adding another two minutes later. By halftime, the Blues were leading 6-0 with additional goals from Alan Hudson (11'), John Hollins (13', pen.), David Webb (23'), and Ron Harris (44').
In the second half, Hautcharage successfully defended their goal until the 61st minute, when Tommy Baldwin increased the lead to 7-0. More goals soon followed, including two more from Baldwin (68', 90'), a second-half hat-trick from Osgood (63', 80', 88'), and one from Peter Houseman (77').
The final score of 13-0 set a single-game Chelsea record and, with a combined score of 21, also beat the previous European aggregate record of eighteen.
Unfortunately for Chelsea, their scoring fortune ended in the next round, where they lost to Swedish side Atvidaberg on away goals, 1-1.