Last updated on .From the section Olympics

Mo Farah successfully defended his Olympic 5,000m title in Rio as Great Britain won 66 medals to surpass their medal haul from London 2012.

Farah's victory added to his gold in the 10,000m as he repeated the distance double he won four years ago.

His medal was GB's 65th before bronze for the women in the 4x400m relay took Britain past the haul from London.

Wins for Nicola Adams and Liam Heath helped take GB's gold tally to 27 as they won six medals in all on Saturday.

Adams successfully defended her flyweight boxing title, while Heath won the kayak single 200m sprint on the penultimate day in Rio.

Farah, 33, is now the world's most successful distance runner in terms of major medals, with nine Olympic and world titles.

The final medal total will be at least 67, with boxer Joe Joyce guaranteed a gold or silver in Sunday's super-heavyweight final.

Day-by-day guide: What to look out for

This was already Team GB's most successful overseas Olympics - eclipsing the 47 medals won in Beijing in 2008 - and is the best medal return at any Games since the 146 amassed in London in 1908.

It is also the first time since the modern Olympic era began in 1896 that a country has increased its medal tally at the summer Games immediately following one it hosted.

Vicky Holland and Bianca Walkden were the other GB medallists on day 15.

Holland won bronze in the women's triathlon, while taekwondo fighter Walkden took bronze in the +67kg category.

Elsewhere, South African Caster Semenya won the women's 800m final and hosts Brazil won men's football gold in a penalty shootout against Germany.

That sixth gold medal made it Brazil's most successful Olympics.

Allyson Felix clinched a record sixth career Olympic gold as the United States won the 4x400m relay for a sixth straight Games, while the US also claimed a sixth straight women's basketball title by beating Spain 101-72.

GB poised to beat China in medal standings

Medal table Position Country Gold Silver Bronze Total 1 US 43 36 37 116 2 Great Britain 27 22 17 66 3 China 25 18 26 69 Latest full table

GB look set to beat China to claim second place in the final medal table, behind USA, thanks to their return of at least 27 gold medals.

"It's been outstanding," said UK Sport chief executive Liz Nicholl.

"We knew we had potentially 79 medal shots - and our target was at least 48 - but really we were aiming for 66, one more than London.

"It shows that the system is working here in the UK. Yet those of us involved know that there's a huge amount more that can be improved, more potential to come. So, as we look ahead to Tokyo, it's looking really exciting."

Arise, Sir Mo?

Farah cemented his place as one of Britain's greatest athletes with his success at the 2012 Olympics in London.

Repeating the feat - winning what has been dubbed the 'double double' - makes him the world's most successful distance runner in terms of major medals.

He is now a nine-time global champion, moving him above Kenenisa Bekele, while his Olympic exploits match Finland's Lasse Viren, who completed the same double at the Munich 1972 and Montreal 1976 Olympics.

"It shows I didn't just fluke it in London," Farah told BBC Sport. "To do it again is incredible. I just want to see my kids and hang this medal around their necks."

BBC commentator Brendan Foster said Farah "deserves to be Sir Mo".

The former Olympic 10,000m bronze madallist added: "He is, for me, the greatest British athlete. Mo, you are a treasure, you are more than a national treasure, you are the greatest we have ever had and one of the greatest distance runners we have ever seen."

US gymnast Simone Biles - a four-time gold medal winner at Rio 2016 - is clearly a big fan of Farah

Adams takes place in history books

Adams won a unanimous points decision to beat France's Sarah Ourahmoune and become the first Briton to retain an Olympic boxing crown since middleweight Harry Mallin in 1924.

"I can't believe I am now officially our most accomplished amateur boxer ever and it is such an amazing feeling," said the 33-year-old. "It takes a lot to win an Olympic medal and I would just like to thank everybody."

Archbishop of York John Sentamu was among those to congratulate Adams on social media

Heath wins second Rio medal

Heath, who won silver in the K2 200m alongside Jon Schofield, went one better on Saturday as he held off France's Maxime Beaumont to claim GB's 25th gold of the Games in 35.197 seconds.

Englishman Heath, a London 2012 bronze medallist, succeeds compatriot Ed McKeever, who failed to qualify for Rio, as Olympic champion.

Holland says sorry, and other GB medals

Holland, 30, won Britain's 62nd medal of the Games with her bronze in the women's triathlon, but was more concerned afterwards with the feelings of her best friend and housemate Non Stanford.

Fellow Briton Stanford was fourth, just behind Holland, following a sprint finish.

"I think the first thing I said to her was 'I'm so sorry'," Holland said. "I knew it would come down to me and Non, which was the worst thing ever because I wanted it to be us together."

Another bronze went to 24-year-old Walkden, who produced two well-timed head shots as she beat Morocco's Wiam Dislam 7-1.

Walkden's success secured GB's third taekwondo medal in Rio after Jade Jones claimed gold and Lutalo Muhammad silver.

GB's third bronze of the day - and their landmark 66th overall - arrived in the women's 4x400m relay.

Eilidh Doyle, Anyika Onuora, Emily Diamond and Christine Ohuruogu finished in three minutes 25.88 seconds to win bronze for GB, the country's first medal in the women's event since 1992.

'Heartbroken' Daley out in semi-final

While there was success elsewhere, diver Tom Daley saw his medal hopes surprisingly slip away in the 10m platform semi-finals.

BBC analyst Leon Taylor described Daley's last-place finish as "unbelievable" and "the biggest turn-up".

Daley, the 2012 bronze medallist, set an Olympic record in winning Friday's preliminary round, but produced an error-strewn display that scored 403.25 points, well off the 571.85 he managed 24 hours earlier.

"I've no idea what went wrong," said Daley. "Training has been going really well, I'm in the shape of my life. I gave it my everything and tried my absolute best. It's just heartbreaking. It's tough to accept."

Other British news on day 15

Mahama Cho narrowly missed out on a taekwondo medal as he finished fourth in the +80kg competition - read more

Joe Choong failed to become GB's first medallist in the men's modern pentathlon after slipping out of contention in the final round - read more

GB failed in their appeal against disqualification from the men's 4x400m relay semi-final - read more

Charley Hull finished just outside the medals as South Korea's Inbee Park won the women's golf - read more

Stat of the day

Niger became the 87th competing nation to win a medal in Rio - a new record for a single Olympic Games - when Abdoulrazak Issoufou Alfaga won silver in the men's +80kg taekwondo final.

Best Olympic videos

Olympics news digest

Russian swimmer Yuliya Efimova has told BBC Sport being at the Rio Olympics was "awful" and "a war". The 24-year-old won two silver medals in Rio but was booed by spectators and criticised by her rivals after she was allowed to compete, having initially been banned by the International Olympic Committee because of two failed drug tests - read more

Nine Australian Olympians were fined for falsifying documents in a bid to get better seats at the Australia v Serbia men's basketball semi-final. Such an offence can carry a prison sentence of up to five years in Brazil - read more

One of the four US swimmers caught up in a scandal over a made-up robbery at the Olympics says he cannot explain team-mate Ryan Lochte's actions. Gunnar Bentz was one of two swimmers pulled off a flight in Rio and questioned by police after Lochte claimed they had been robbed at a petrol station - read more

Day 16 highlights - what to watch

All times BST:

13:30 - Men's marathon starts

19:15 - GB boxer Joe Joyce fights for gold in the super-heavyweight final

19:45 - The United States men's basketball team bid for gold against Serbia

00:00 (Mon) - Closing ceremony begins (BBC One from 23:25 BST)

Full Rio 2016 schedule