It started with Diogo Dalot losing his bearings. It ended with Bruno Fernandes losing his mind.
For 10 minutes either side of half-time Liverpool ran roughshod over a shellshocked Manchester United to truly find themselves again and let their rivals know that it would take more than a few good results and a League Cup before they could truly claim to be back to former glories.
For 42 minutes it had been a pretty even affair, and one often short on quality in the key areas, with a final pass or miscontrol letting players from both sides down.
It had been frantic, obviously, because that's this fixture. Much of the action seemed to be taking place down the Liverpool left where Andy Robertson was enjoying a running battle with Antony which left the Brazilian more than a little wound up.
Jurgen Klopp was spending most of his time glaring at referee Andy Madley following his failure to award to foul to Mo Salah after he was caught by Lisandro Martinez. Tempers were frayed, but the surface remained unbubbled.
Then Dalot wandered too far forward.
It was at that moment Robertson played his superb pass inside a sleeping Fred, and there was Cody Gakpo cutting inside and unleashing a superb finish right in front of supporters he could have been playing for.
From that moment on there was only one winner of this game, and one side who had the belief to take the game away from their shellshocked visitors.
In truth United were lucky that half-time came when it did, but if that was supposed to herald a change of mindset and regathering of themselves for Erik ten Hag's side then it never arrived. In fact they never did.
Liverpool swarmed all over them, the front three of Salah, Gakpo and Darwin Nunez everywhere as United became frozen in fear.
Luke Shaw, Casemiro and Wout Weghorst all could and should have dealt with the ball as it snaked toward the United goal, but suddenly it was with Harvey Elliott and then on Nunez's head. 2-0.
Three minutes later, even better.
As United began an inquest into just what was going on, Liverpool didn't hang around.
Salah was free down the right and then there was Gakpo and a beautiful dinked finish. United's defence were nowhere to be seen.
Almost out of embarrassment the visitors then came forward, and it was Marcus Rashford and Bruno Fernandes carrying the fight, although Fernandes' anger was reserved for referee Madley as he first failed to get a corner and then fumed with the Liverpool fans after he was beaten to the ball by a slipping Alisson.
The damage was done now, and United shambled their way through the remainder of a game in which they embarrassingly shipped another four goals, each one celebrated louder than the last.
Those mad 10 minutes mad it happen though, and you wonder if they'll ever recover.
