Arsenal restored their five-point Premier League lead over Manchester City with a 3-2 victory over Manchester United on Sunday.
A late strike from Eddie Nketiah gave the Gunners all three points at the Emirates after City had earlier seen off Wolves 3-0 as Erling Haaland netted a fourth hat-trick of the season.
But it was Roy Keane's moustache that had many football fans talking before, during and after the game as the former United captain did punditry on Sky Sports.
A number of them were in favour of the tash, with one writing: "So much to enjoy as an #AFC fan right now… but all I can think about is Roy Keane’s amazing moustache."
Another commented: "My biggest concern from the Emirates is Roy Keane's moustache, and how much I dig it.."
Someone else posted: "Regardless of the result the real winner today is Roy Keane and his Moustache."
"I’m enjoying Roy Keane’s moustache," read another comment.
One other fan added: "The moustache really suits Roy Keane it has to be said."
But not everybody agreed with those comments, as one viewer wrote: "Don't know whether to respect or fear Roy Keane 's moustache ."
Someone else tweeted: "What is Roy Keane 's moustache all about?....."
"That moustache isn’t doing Roy Keane any good," read another comment.
One other fan posted: "If I grew a moustache. It wouldn’t be far off Roy Keane’s. That why I don’t grow a moustache!"
"Man Utd deserved to lose just for that horrendous moustache on Roy Keane," concluded another.
While fans debated Keane's moustache on social media, one Twitter user pointed out how many different facial hair styles Keane has had in the past few weeks.
They said: "Roy Keane’s facial hair cracks me up because how does it grow that fast? In the last two months I swear I’ve seen him clean-shaven, with a full beard and various moustaches."
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