Now here's something you never thought you would see.
One Manchester United fan pushed his luck a little too far when he turned up in club colours to a Liverpool training session in Malaysia.
It wasn't long before fans of the Merseyside giants saw the offending shirt, and he was made to take it off, before being bundled away from proceedings.
What's he doing here? A United fan turns up to a Liverpool training session
One doesn't need to be a walking encyclopaedia of footballing facts to know that the story of United and Liverpool is in many ways the story of the game's post-war history in England.
Liverpool were totally dominant throughout the 1970s and 1980s, before Sir Alex Ferguson and a succession of brilliant United teams altered the landscape of the game.
Banner: United fans unveiled a special message at Anfield at the end of last season
Feelings always run high when supporters of the two biggest clubs in England meet. At the end of last season, United fans bravely went to Anfield and unfurled a '19 times' banner, after the club had overtaken Liverpool and their 18 championship wins.
Liverpool fans had at one time taunted their rivals with their success, unfurling their own banner back in the 1990s telling United fans to 'come back when you've won 18'.
Liverpool fans, look away now: Manchester United players celebrate a 19th league title last season
Who knows which way football's cycle will turn in the years to come? The only certainty is the continuing intensity of this long-standing rivalry.
WATCH A VIDEO OF THE BRAVE FAN.
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