Linked by Angus Abranson: The day UFOs hovered over Fiorentina’s Stadium in 1954. That’s one way of getting a good seat for the match...
More, including reports of sticky “angel hair” falling on the city before evaporating, like Spider-Man’s webbing, as well as tales of hauntings and hexes in other stadia.
Normally Unidentified Flying Objects that stay Unidentified are reported over Nowhere In Particular (Population Three) which is why something like this is still worth noting sixty years later.
As discussed on DWAITAS lately, alien incursions and UNIT activity were out in the open in the Davies era, although often conveniently denied, but now they’re largely secret again as the Doctor and his world retreat into the shadows.
So you can still have the “whoa” moment of first contact when alien craft appear over our famous landmarks... even though first contact has happened loads of times now.
Having Londoners shrug it off like it’s nothing special (until it starts shooting lasers) can work just as legitimately, but mass panic is still an option.