A Middlesbrough fan was arrested for child neglect after leaving an 11-year-old alone in a hotel to celebrate the Championship side's FA Cup victory against Manchester United.
Middlesbrough booked their place in the fifth round of the competition by beating the Premier League team on penalties at Old Trafford on Friday night.
The visiting fans celebrated their surprise win against Ralf Rangnick's team, but Greater Manchester Police Stretford has confirmed an arrest.
"'Boro away fan arrested for child neglect last night, after choosing to leave his 11yr child in the hotel after the game whilst he went into town celebrating their victory drinking," GMP Stretford announced on Twitter.
"We have looked after the child with an unhappy mum on her way down from N/East to collect him."
The home side took the lead in the FA Cup fourth-round match with a goal from Jadon Sancho after 25 minutes.
Middlesbrough pulled level in the second half when Matt Crooks fired past Dean Henderson.
The goal was a controversial one, however, as United players surrounded the referee and called for a handball in the build-up.
But a VAR check ruled that Duncan Watmore's handball was accidental and the goal was allowed to stand.
The game went into extra-time and then penalties, with the visitors going on to win 8-7 after Anthony Elanga missed his spot-kick for United.