Romelu Lukaku took a little glance over his shoulder, just to check his surroundings, before the head went down and the legs started to pump. Picking up the ball near the centre circle, the Belgian surged forward towards the backpedalling Napoli defence, eating up the ground in front of him and assessing his options.

A stepover followed, then a shift of the hips, and before the defenders could react the ball was in the corner of their net. Eight seconds had passed since Lukaku received possession inside his own half, and in those eight seconds there was barely a moment of doubt over whether the Inter Milan striker would punish his opponents.

Of the 21 goals Lukaku has plundered for his new club, it was this strike, away to Napoli last month, that best underlined his transformation this season. It was raw, uncensored Lukaku: a striker at the top of his game, playing to his strengths in a team which thrives on aggressive, front-foot football.

They have not all been like that. There have been tap-ins, too, and long-range screamers. Then there are the close-range finishes, the clinical penalties and the towering header like the one he scored against AC Milan on Sunday night. "There's a new king in town," he later said on social media. It has all been there for Lukaku, who is looking for all the world like the all-round striker Manchester United were so desperate to recruit last month.