Prime Minister David Cameron congratulated German chancellor Angela Merkel by text message over her country's victory in last night's football World Cup final.
He sent the text after watching the thrilling last half-hour of the match, which saw Germany seize their fourth World Cup title - and their first since reunification - by beating Argentina 1-0 in extra time.
Germans celebrated late into the night in pubs and bars in London.
Mr Cameron's official spokesman said that the PM had been unable to watch the first 90 minutes of the match, which ended 0-0 after ordinary time in Rio de Janeiro, as he was travelling back to Downing Street from his country retreat Chequers. He switched the TV on to watch the extra time after returning to Number 10.
"The Prime Minister texted his congratulations to the German Chancellor after Germany's victory last night," said the spokesman, who declined to reveal the wording of the message.
Mrs Merkel was present for the match and jumped for joy as Mario Goetze's winning goal went in. She later congratulated the team as they went up to be presented with their medals and trophy, as well as posing for a selfie photo with them.
German-themed pubs and bars across London were filled with delighted ex-pats celebrating into the early hours.
At the Zeitgeist pub in Vauxhall several hundred fans of Die Mannschaft erupted with joy at the final whistle, spraying beer everywhere to start a party that went on long into the night.
One fan, called Jorg, said: "It's unbelievable. This is the second World Cup I have witnessed us winning since I was born, the first I was too young to realise, this one has been a dream."
Philip Naggert, from the German city of Bielefeld, joined many fellow countrymen celebrating in Trafalgar Square.
He said: "I feel amazing, I can't believe we won this. And Goetze scored, it is incredible, it's the best feeling ever."
The mood was in stark contrast to that in Argentinian bars across the capital.
Around 400 noisy fans gathered at Moo Cantina in Pimlico to cheer on the South Americans.
Many wore their team's blue and white shirt and painted their cheeks in support of their heroes.
They chanted constantly throughout the game until Goetze's goal in the 113th minute left everyone in stunned silence.
Some fans were left in tears and could not bring themselves to watch the dying moments of the game.
But when the final whistle was blown the fans gave a rapturous round of applause for their team's efforts.
Some left the venue with glum faces, but many others held a party outside, setting off fireworks and dancing.
Caro Serrizvela, 31, of Bayswater, said: "I'm very happy and very proud of how we played. But in the World Cup the most important thing is to win."
Daniel Caballero, 34, who lives in Stoke Newington, said: "I think that was our best performance. Everyone thought the Germans would score three or four goals but after 90 minutes it was 50/50.
"Someone has to win at the end."
His wife, Chantal, 26, said: "Both teams had good chances. I was suffering for 120 minutes. It would have been nice to see Messi lift the World Cup."
Alex Hughes, 26, who grew up in Argentina and now lives in Peckham, said: "I feel destroyed but extremely proud. I felt it deserved to go to penalties.
"Germany managed to shut Messi down. Possibly he played too deep."
Hernan Palacios, 33, of Bromley, said: "We almost won the World Cup, so if you don't win, second place isn't enough."
The final broke records with the most tweets per minute of any event posted during the game.
There were 32.1 million tweets about the match worldwide, with around 618,725 made per minute, official figures from Twitter showed.