Thousands of football fans watched Barcelona beat Manchester United in a dramatic Champions League final at Wembley stadium.
Barcelona took the lead only for Manchester United to equalise, but in the second half the Catalans scored twice more to win the game 3-1.
There was a huge police operation in London and Manchester on Saturday.
A Metropolitan Police spokesman said by 1230 BST on Sunday there had been 44 arrests.
Most were for public order offences but there were also arrests for criminal damage, theft and burglary.
Up to 300 million people were expected to watch the match worldwide.
The bumper viewer figures are expected partly because the final was held on a Saturday for only the second time, and also because both clubs have such a huge global following.
It was billed as the biggest sporting event in the UK until the London 2012 Olympics.
After the game, Manchester United's Rio Ferdinand said: "On the day they were the better team so we can't really argue. They are a great side with great players."
Many Manchester United fans agreed.
One said: "Barcelona are the greatest team on the planet right now and they played like it. Well done to them."
Another said: "I am disappointed but they were the better team."
Fifa president Sepp Blatter did not attend the game because he is preparing for an ethics committee hearing following bribery allegations.
Blatter has not commented on the proceedings but said: "The facts will speak for themselves."
Sir Alex Ferguson decided to start with Javier Hernandez up front, alongside Wayne Rooney.
But surprisingly there was no place, even on the substitutes' bench, for striker Dimitar Berbatov.
Barcelona took the lead on 27 minutes with a goal by Pedro Rodriguez but United equalised soon afterwards through Rooney.
It was level at half time but Lionel Messi put the Catalan side ahead early in the second half.
David Villa made it 3-1 as Barcelona dominated the second half.
Some 1,000 police officers were involved in the operation across London. Officers from the Spanish force were on duty in London during the game.
"A Catalan-speaking officer from the Met will be liaising with the Spanish police during the event and will be on hand to assist with fans if required," a spokesman said.
Each club had 25,000 supporters with match tickets, although an estimated 110,000 fans were thought to have travelled to London for the final.
Pubs in the area closed an hour before kick-off and no alcohol was permitted inside the stadium.
Before the match began, many fans tried to acquire last-minute tickets outside the stadium.
Earlier in the day Barcelona fans gathered in London's Trafalgar Square where Nelson's Column was festooned with flags.
A major policing operation also took place in Manchester.
Extra patrols were carried out in the city centre as supporters filled pubs and bars to watch the match.