Manchester United manager Ole Gunnar Solskjaer confessed the 6-1 home defeat to Tottenham was his worst day in football.
Ten-man United sunk to their joint heaviest Premier League defeat ever as Jose Mourinho's men ran riot at Old Trafford to darken the club's already bleak mood significantly.
Solskjaer, whose position will surely now come under threat after this embarrassing loss, saw his side capitulate after going in front inside two minutes through Bruno Fernandes' penalty.
Son Heung-min and Harry Kane scored two each, with Tanguy Ndombele and Serge Aurier also getting on the scoresheet as Mourinho's men made an impressive statement.
The inquests have already begun, with former Red Devils full-back Patrice Evra describing them as a shambles and club great Gary Neville said their performance was "an absolute shambles" as United matched the 6-1 loss to Manchester City in 2011.
The Norwegian, whose club are reportedly closing in on a deal to sign Alex Telles from Porto and free agent Edinson Cavani, said he shoulders the blame.
"It's very embarrassing, it hurt all the players," said Solskjaer. "It hurts me as the manager. It's my worst day ever.
"I'll hold my hands up, I'm responsible for this. I've lost 5-0 with United and we've lost 6-1. We've lost big results before and always bounced back. I promise we'll do everything we can to turn this around.
"We know how good they can be but today all our mistakes came almost like Christmas, everything at once. If you make too many mistakes against a good team you'll be punished."