Ninety-eight seconds. That was all it took for Ruud van Nistelrooy’s reign at Leicester City to begin. Jamie Vardy’s opening goal also offered an early snapshot of Leicester in Van Nistelrooy’s frame. Victor Kristiansen, hugging the left touchline, passed the ball to Bilal El Khannouss, who freed Leicester’s No.9 with his head down and deployed in the left channel. Vardy, wearing bright pink boots, fired a timeless right-footed shot into the far corner.

After a VAR check, he went into celebration mode and whistled to the away fans, which caused him distress. Even before Patson Daka made it 3-0 in stoppage time, the same fans turned their attention to their manager. “You will be released tomorrow morning,” the chant rang out. Julen Lopetegui, ashen-faced at the final whistle, will do well to overcome this horrific defeat. Lopetegui ran a hand through his hair, his whirring mind in overdrive, under pressure. Welcome back to the brutal world of frontline management, Ruud.

Van Nistelrooy is back on the train, as he put it, this merciless hamster wheel. For most of this game he stayed on the edge of the home technical zone, quietly observing, rarely more than a few meters from Lopetegui, although the two could hardly be in different places. One is confident he can resume his coaching career in the dugout, the other is clinging to his job after another devastating defeat.

West Ham are looking for successors in case they decide to hit the reset button. Van Nistelrooy might even have had a whiff of the job if he had still been unemployed. As interim manager of Manchester United, following the draw against Chelsea at Old Trafford last month, the Dutchman questioned Enzo Maresca, who led Leicester to the league title last season, about the club’s health and structure, with a view to replacing Steve Cooper.

Now Van Nistelrooy is Leicester’s king. In the seconds before kick-off he was applauded on all four sides of the pitch and within ten minutes sections of the home team were boisterously chanting his name shortly after Lukasz Fabianski had deflected another Vardy shot into the side netting following another Kristiansen pass.

In a way, Leicester have reverted to type. Van Nistelrooy’s side generally played a 4-4-2 without possession, Facundo Buonanotte formed tag teams with Vardy in front of two benches of four, and with the ball they slipped into a 3-4-3 with a box in midfield. “It’s something that was very well developed here when Enzo came in; “Obviously the team was much more dominant in the championship,” said Van Nistelrooy. “I saw it as an advantage to come here.”

The result flattered Leicester, who could easily have been 6-1 down at half-time. They may have changed managers but Mads Hermansen has been a constant since his arrival from Brøndby last year, the goalkeeper proving to be a talented signing; Only Mark Flekken has made more saves in the top flight this season.

Hermansen made an excellent save from Jarrod Bowen in the first half and redirected a clumsy effort from Mohammed Kudus over the crossbar early in the second half. Danny Ings let a header hit a post, Carlos Soler and Tomas Soucek went close. Two minutes before El Khannouss gave Leicester some breathing room, Hermansen was lucky that a strike from Soucek was enough for the referees to award a foul and not a West Ham goal.

So it was good that Van Nistelrooy had concentrated on defensive work in his first training session with the entire team 24 hours earlier. West Ham finished with 31 shots, 10 of which were on target. Conor Coady prevented Crysencio Summerville from conceding a goal by clearing the ball on the line with his big toe. “It was similar when we took over United,” said the Leicester manager. “In our first game against Leicester (United won 5-2) we showed energy, commitment and fight… it got the crowd going. When you have that connection behind you, it increases your performance.”

Between his jobs at PSV Eindhoven and United, Van Nistelrooy spent time in Argentina and Spain and visited Carlo Ancelotti at Real Madrid’s headquarters in Valdebebas. Such is the palatial and plush nature of the facilities at Leicester’s Seagrave training base north of the city, Van Nistelrooy said, if they changed the logos at the place it could easily be mistaken for the home of the La Liga team.

This time last year, Van Nistelrooy spent ten days accompanying Ancelotti, the master of quiet leadership. Van Nistelrooy clenched his fists as El Khannouss doubled Leicester’s lead but everything was under control. He didn’t stay on the pitch to accept praise at the final whistle, despite making a dream start to a new era. With his head bowed and his hands in his pockets, Lopetegui didn’t bother to go anywhere near the fans traveling with him. He knows his time may be up.