Lookman looked likely to earn the Cottagers a point when he stepped up to take a penalty six minutes into additional time at the London Stadium on Saturday.
Hammers goalkeeper Lukasz Fabianski could scarcely believe his luck as Lookman's impudent Panenka effort – a penalty chipped down the middle and into the net – backfired spectacularly.
In short, see the penalty below…
The abysmal attempt drifted harmlessly into the grateful Fabianski's arms and proved to be the last kick of the match as West Ham won after a farcical finish.
One stunned fan questioned whether the shocking spot-kick was the worst penalty of all time.
‘And in the 97th minute,' they boggled. ‘What is he thinking?'
Another asked: ‘Who takes a penalty this way with the last kick of the game? A kick that should have earned a point.'
Others cruelly joked that Lookman would be shunned at Fulham's training ground on Monday and compared his fiasco to successful Panenka penalties taken by the likes of Spain legend Sergio Ramos and Argentina icon Lionel Messi.
This article was most recently revised and updated 2 years ago