A record audience of 8.6 million tuned into Channel 4 for the last episode of long-running sitcom Friends on Friday.
The stars earned a reported $1m (£545,000) per episode
The network said more than a third of the UK's TV viewers saw characters Ross and Rachel end up together in an emotional climax to the US series.
At the height of the hour-long episode broadcast at 2100 BST, 8.9 million viewers were watching, Channel 4 said.
It beat the previous highest rating for Friends for an episode in June 2002 which drew 6.5 million viewers.
Alongside the Big Brother launch programme that followed, it was also Channel 4's most watched programme of the year.
It beat Grand Designs with 5.9 million viewers, and Ramsay's Kitchen Nightmares (5.6 million). Big Brother had 6.7 million viewers.
The hour-long Friends special had been seen by 51.1 million people in the US, where it commanded advertising rates averaging $2m (£1.1m) for 30 seconds.
But it may not be the last UK audiences will see of Monica, Phoebe, Rachel, Ross, Joey and Chandler.
Actor Matt Le Blanc has a spin-off series lined up, while Friends repeats are a fixture of C4 schedules.
British newspapers had already revealed the fate of the six after the last episode was shown in the States.
The show ends with Monica and Chandler discovering they were having twins via a surrogate mother.
Phoebe and her husband Mike decide to try for a baby, and Joey stays in the apartment but is to move to Los Angeles to try and break into Hollywood.
The station had hoped to draw millions of viewers to the launch of Big Brother 5 by screening the reality show straight after the Friends last episode.
The idea paid off with at least 6.7 million viewers tuning in at 2200 BST to watch the latest batch of contestants go into the house.
Friends has been a consistent ratings winner for the British channel and its pay-TV spin-off E4.
In all 234 episodes of Friends were made over a period of ten years.
The show made stars, and millionaires, out of LeBlanc, Jennifer Aniston, David Schwimmer, Matthew Perry, Lisa Kudrow and Courtney Cox Arquette.
Over the years viewers have seen Ross and Rachel hook up, break up and have a child together.
They have seen Phoebe have triplets, Chandler and Monica marry and Joey woo countless females.
They have also seen innumerable cups of coffee downed in the friends' regular watering hole, Central Perk.
The screening of the last episode became a huge event in the US, with thousands watching on a big screen in New York's Times Square.
US network NBC is hoping audiences will show the same loyalty to spin-off show Joey, in which LeBlanc's character moves to Los Angeles to pursue his acting career.