Image caption Anthony Joshua (left) turned down an offer to go professional, saying 'I want to win medals'

Team GB boxer Anthony Joshua has ensured a golden end to London 2012 with victory in his super-heavyweight bout on the final day of competition.

He beat Italian Roberto Cammarelle to win GB's 29th gold medal of the Games.

With the sun shining, tens of thousands of spectators lined London streets for the men's marathon and a farewell concert in Hyde Park.

Once the sport has concluded, the closing ceremony is due to start at 21:00 BST.

Team GB have one final chance of medal glory in the modern pentathlon, which is due to finish at 18:30 BST.

World bronze medallist Samantha Murray lies in third place overall after the swimming, while world champion and GB teammate Mhairi Spence is ninth.

'Life experience'

A post-bout appeal against Joshua's victory by the Italian team was rejected after a countback by the judges.

Reacting to his win, Joshua said "Sunday is a holy day and I have been blessed".

He added: "That medal represents my journey and the support from my team. It is much more than a gold medal, it is a life experience."

At the scene The sun gods have smiled on these Olympics, mostly, and the last day of competition and celebration here is a glorious one. Just water polo and handball finals to go now, and the closing ceremony. The feeling is quite international as fans from six European nations make their way to and from stadiums showing sports that do not traditionally have a strong following in the UK. Other venues are silent. The blue and pink stands of the hockey venue, which vented so much noise from the crowds these last two weeks, are completely empty.

Welsh fighter Fred Evans had to settle for silver in his welterweight bout against Serik Sapiyev from Kazakhstan.

The 21-year old said: "He [Sapiyev] was sharper on the day and I didn't stick to my plan quite as I should have."

One of the Olympics' most iconic events, the men's marathon, took place earlier on the streets of London.

Thousands of people gathered for the free event, which started at 11:00 BST at The Mall. The gold went to Uganda's Stephen Kiprotich.

The BBC's Margaret Ryan joined spectators on the marathon route and said spectators from a myriad of countries were "savouring every moment of the last day of the Olympics".

Meanwhile crowds have packed the live site at London's Hyde Park, to watch the action on the big screens and enjoy a farewell concert which is being headlined by Blur.

After 16 days of competition at the Olympic Park, plus venues throughout London and elsewhere, London will hand over to 2016 host city Rio de Janeiro in what promises to be a stunning show involving 3,500 performers in the Olympic Stadium.

After the last three weeks the question might now be: How can anyone hope to follow London? David Bond, BBC's Sports Editor How can Rio follow London?

Artistic director Kim Gavin said the ceremony would be "the best after-show party of all time".

The final tickets - a few hundred released after the set was put in place - were sold overnight.

Called the Symphony of British Music, the event will showcase "British creativity in the arts" and take people on a musical journey from Elgar to Waterloo Sunset in 30 tracks, Mr Gavin said.

Singer George Michael has already confirmed his participation and the Spice Girls and Tinie Tempah are among acts reported to be performing.

During the ceremony, sailor Ben Ainslie, a four-time Olympic gold medallist, will carry the flag for Team GB.

Image caption Thousands of spectators lined London streets for the men's marathon

Team GB chef de mission Andy Hunt said: "In becoming the most decorated sailor in Olympic history, Ben has earned the honour of leading our delegation into the closing ceremony of these extraordinary Games."

Britain is in third place in the medal table, surpassing the medal achievements of Beijing four years ago, and recorded the biggest haul since the London Olympics of 1908.

Mr Hunt said Team GB had "unquestionably" exceeded expectations.

"What's come together is a dream. I would say this is our greatest performance, of our greatest team, at the greatest Olympic Games ever," he told the BBC's Breakfast programme.

In other developments:

At the scene In a corner of south west London, Tooting Bec Lido had a sprinkling of Olympic magic as Ian Thorpe gave up his morning to hand out swimming tips to young and old alike. The water was freezing but that didn't stop a large group of people queuing up to get tips from the five-time Olympic champion. It was Thorpe's idea to come hot-foot from the Olympic park to Tooting to kick-start the much-talked about legacy of the London 2012 Games. And if this start is anything to go by it could be a stellar legacy. Whether passing on tips about head position on backstroke to a three-year-old boy or on front crawl kicking to a group of adult swimmers, Thorpe had time for them all and even ran the risk of missing his taxi back to the Olympic park as he stayed to sign autographs and pose for photos.

'Lifted country'

Mr Cameron said the Olympics had been an "extraordinary few weeks" which had "lifted the whole country and there was a "huge opportunity" to build the legacy for the Games.

He said legacy had been "built into the DNA of London 2012 from the very beginning" and he was "determined to make the most of the economic opportunities on offer from hosting the Games - making sure that we turn these Games into gold for Britain".

Speaking about Lord Coe's appointment, he said: "I cannot think of a better person than Seb to be our ambassador to the global market-place and make sure we achieve our ambitious legacy targets."

Lord Coe said he was "very happy" to drive the legacy forward but it was not a "one-man mission" and the "whole nation" had to support its values.

He said he thought there would be "fundamental changes" to London after the Games.

The International Olympics Committee president Jacques Rogge said he was "very happy" with the Games, and he was a "very happy and grateful man".

"It has been a dream for sports lovers," he said, adding that history had been made by many athletes.

The London organising committee, Locog, said the total cost of the four Olympic and Paralympic opening and closing ceremonies stood at £81m, with the opening ceremony costing £27m.

The revamped 560-acre (227-hectare) Olympic Park site - to be known as the Queen Elizabeth Olympic Park - is set to reopen in stages starting on the first anniversary of the opening of the Games, on 27 July 2013.