Chiheb Ellili has quit as coach of Tunisia's Club Africain after their record 8-0 loss in the African Champions League group stage to TP Mazembe.
The Congolese side's impressive win on Saturday eclipsed the mark set 18 years ago by Ivory Coast's Asec Mimosas.
Ellili had only been in charge of the club since October 2018.
"My resignation is out of respect for the club's fans, I take a big part of the blame for Saturday's heavy loss," he told radio station Mosaique FM.
"The loss of yesterday is, for me, an accident of course because the team is on the right track"
"Too bad for the players, who have given everything for months, to lose in this way.
"On a personal level, I think this is the worst moment of my career. I'm a fighter and a winner and I really did not want to live this nightmare."
The club is yet to name a replacement for Ellili.
The loss left Club Africain bottom of Group C without a single point so far from two matches.
Algeria's CS Constantine top the group, which has been reduced to three teams following the disqualification of Egypt's Ismaily, with a maximum six points with Mazembe on three.