Boris Johnson tripped up on a football question when he was quizzed about modern British history during a radio chat on Friday.
When asked who scored a hat-trick for England in the 1966 World Cup final, the London Mayor incorrectly answered Bobby Moore.
Striker Geoff Hurst famously scored a hat-trick in the Wembley match, a 4-2 win for England against West Germany, while defender Moore was the team's non-scoring captain.
It is regarded as one of the greatest moments in English sporting history.
"I was only two!" protested Johnson after getting the question wrong.
The Conservative politician was being grilled by LBC radio host Nick Ferrari in the wake of a similar quiz for Prime Minister David Cameron on the David Letterman show.
London Mayor Boris Johnson has said that Prime Minister David Cameron was "only pretending" when he failed to correctly answer a question on the Magna Carta during an interview on the Late Show with David Letterman this week.
Speaking to LBC 97.3 Radio's Nick Ferrari, the Mayor, who has appeared on the programme himself, said:
I think he (Prime Minister David Cameron) was only pretending, I think he knew full well about the Magna Carta. It was a brilliant move in order to show his demotic credentials and to show he didn't have Latin bursting out of every orifice.
David Cameron has today fended off rumours that London Mayor Boris Johnson has his eye on the Conservative leadership and the country's Prime Minister role.
In an interview for Brazilian newspaper Folha de Sao Paulo, the British Prime Minister was asked: "With the economy in crisis, we see mayor Boris Johnson, also of your party, with greater popularity than you.
"To the point there are rumours that he might be the Conservative candidate for the next general election. Do you feel your post is threatened?"
Mr Cameron responded by saying: "Not at all. Boris has been a great friend of mine for a long time and a first-class mayor of London.
"We're very lucky to have many big hitters in our party, but Boris still has much work to do as mayor, and so do I as Prime Minister."
– David Cameron
I'm a history obsessive, so I'm sorry I didn't do better.
I think, when I get home and do my children's homework, maybe I need to sit down and do a little bit extra myself.
After David Cameron failed his British culture test on the David Letterman show we put London Mayor Boris Johnson to the test today.
Watch the video below to see if Boris knew that Thomas Arne composed Rule Britannia and that Magna Carta translates to Great Charter.
David Cameron spoke about the differences between US and UK political campaigns in his appearance on the Late Show with David Letterman.
David Cameron has appeared on a high profile late night US chat show. Speaking on the Late Show with David Letterman, the prime minister praised the effort of athletes and spectators at the Olympic and Paralympic games.
"There were no empty seats in the stadium.
"I think the message about disability the world over showed what disabled people can do as opposed to what they can't do.
"It was very very powerful."
Ouch! David Cameron may regret ever appearing on the David Letterman show. He was ambushed by the host asking him a British history quiz.
And, yes, he flunked it. Cameron even joked at the end: "That is bad - I've ended my career on your show tonight."
But hold on. Here is the surprising thing. The audience loved Cameron.
Every single person I spoke to as they left the theatre where the show is recorded gave the Prime Minister the thumbs up.
They thought he was amusing and charming. I repeatedly asked people to rate Cameron's performance. Most gave him 10 out of 10. The worst I could get was an "8."
That may not change the "PM is left red-faced" headlines that are sure to be in the British papers this morning. But it means he played well in the American heartland, which afterall was the target audience.
Here's the only conclusion I can draw: Americans are a very forgiving lot.