The Ethiopian chased down Emmanuel Mutai, and overtook the Kenyan in the closing stages to cross the line first in front of Buckingham Palace.

Kebede, who like most competitors wore a black ribbon to mark the Boston victims, clocked 2 hours, 6 minutes and 15 seconds to add to his 2010 triumph in London. 

In the women's race Kenya's Priscah Jeptoo went one better than her London 2012 Olympics silver by winning the Virgin London Marathon today.

The 28-year-old clocked two hours 20 minutes 15 seconds to win comfortably ahead of her fellow countrywoman Edna Kiplagat.

Japan's Yikiko Akaby was a surpise third, with Olympic champion Tiki Gelana paying the price for a nasty fall.

Just 15 km into the race, Olympic marathon champion Gelana collided with wheelchair racer, Josh Cassidy.

The Ethiopian runner attempted to cut across the wheelchair racers to grab her water bottle. Unfortunately,  she cut it too fine and had the backs of her heels clipper by a weel. Reports suggest that the wheelchair ran over her leg as she feel.

Cassidy, the wheelchair racer who won the London event in 2010, had to retire and later raged at organisers.

He warned organisers that there was a risk of an athlete suffering serious injury if the wheelchair racers did not start getting under way first.

Gelana, the Olympic champion, cut inside to reach the drink stop, but hit Cassidy as he came up the inside and fell heavily.

Both athletes were able to rejoin the race, but the incident put paid to their hopes of success, with Cassidy coming home in 20th place, almost 11 minutes behind the winner.

Cassidy told the BBC: "It's something I have mentioned before.

"I don't know who's responsible, but every year we come to overtake the women, there's 10 chairs going at 20mph and the poor women are scrambling to find their feet.

"I have a brand new 2,000 dollars pair of wheels that are damaged, who's going to pay for them? Things have to change.

"The safest thing would be to have the chairs start first because one of these years a woman is going to have a leg broken, a career ruined. It's just not worth having this programme if the races are going to suffer."

David Weir avoided a collision, but his bid for a record seventh title ended in disappointment as he came home fifth.

Weir, who banished any thoughts of retirement after his four gold medals at London 2012, had no answer to his rivals' power off the final turn as Australia's Kurt Fearnley claimed victory.

The 33-year-old, sporting a werewolf logo on his red helmet in homage to the 'Weirwolf' nickname he was given at the Paralympics, came home in one hour 31 minutes 31 seconds, two seconds adrift of Fearnley.

It means Weir is still level on six wins with Tanni Grey-Thompson.

Weir was not too downbeat, saying: "It was going to be tough to get back into the swing of things. I had four months off (after the Paralympics).

"I always struggle the year after, but I am happy, you can't win all the time. I'll bounce back."

American Tatyana McFadden claimed victory in the women's wheelchair race, just six days after winning the Boston Marathon.

She set a new course record with an unofficial time of 1hr 46mins 02secs to edge out compatriot Amanda McGrory.

Great Britain's Shelly Woods, the defending champion, was fifth.

McFadden had said in the build-up to the race she would compete with the victims of the Boston bombings "in her heart".

She said: "Our thoughts are still with Boston."

In the inaugural IPC (International Paralympic Committee) Athletics Marathon World Cup, double above-the-knee amputee Richard Whitehead finished in 3:15.53.

Whitehead won the T42 200 m at last summer's Paralympics and was the only athlete in his class in today's race.

Elsewhere, Mo Farah remained true to his word as he dropped out of the Virgin London Marathon just before the halfway mark today.

The double Olympic champion crossed Tower Bridge in the leading group, which reached 20 kilometres in 58 minutes 28 seconds, before slowing and stepping off the course.

The 30-year-old was comfortably keeping pace with a strong field, which included the world record holder and all three medallists from the 2012 Olympics.

Farah's plan to run to halfway, as preparation for making his debut on the streets of the capital next year, had met with anything but universal approval in the build-up to the race.

Critics accused him of putting money ahead of morals and he admitted the harsh words had hurt.

But he received a warm reception when introduced to the crowd at the start and it continued throughout his race.

"It was incredible. The amount of support, people coming up from everywhere, just cheering the whole way... unbelievable," he told BBC1.

"I didn't think there'd be as many people as today. They're just cheering, coming up from houses, on the roof... the atmosphere's incredible."

Farah had constantly stressed in the build-up he was treating the race as a practice outing and a means of gaining experience for going all the way to the finish next year, and he revealed he had learned some important lessons.

He added: "It's not a problem with the pace. The pace looks good and obviously I've got to get past halfway.

"I think the biggest challenge for me is picking up the drinks and making sure you pick up the right drink and I made a mess of it - I think it was up at 10k."

Asked if the experience had been worthwhile, he replied: "Definitely. I've learned the biggest lesson of my life, really.

"If I would have come out here next year and made a mess of it, mentally it's hard to deal with that. So it's a good practice for me - waking up here in the morning, being round here, dealing with the media and everything.

"I've learned a lot, for sure. I'll probably watch back this race and see how much of a mess I made of the drinks."

Derek Hawkins was the first Briton home in 13th place in 2:16.50, with Olympian Scott Overall dropping out just after halfway.

In the men's wheelchair race, David Weir's bid for a record seventh London Marathon title ended in disappointment as he came home fifth.

Weir, who banished any thoughts of retirement after his four gold medals at London 2012, had no answer to his rivals' power off the final turn as Australia's Kurt Fearnley claimed victory.

The 33-year-old, sporting a werewolf logo on his red helmet in homage to the 'Weirwolf' nickname he was given at the Paralympics, came home in 1:31.31, two seconds adrift of Fearnley.

It means Weir is still level on six wins with Tanni Grey-Thompson.

American Tatyana McFadden claimed victory in the women's wheelchair race, just six days after winning the Boston Marathon.

She set a new course record with an unofficial time of 1:46.02 to edge out compatriot Amanda McGrory.

Great Britain's Shelly Woods, the defending champion, was fifth.

McFadden had said in the build-up to the race she would compete with the victims of the Boston bombings "in her heart".

Preparations for today's race were overshadowed by the attacks which killed three people and there was a moving 30 seconds' silence ahead of the start of the elite men's and mass races.

Security in the capital was beefed up to ensure the safety of spectators and athletes alike.