The 23-year-old Welshman swam himself to exhaustion after putting in a blistering burst of pace in the final 500 metres of the race in an attempt of burn off the rest of the field.

But he just lost out in the final 100 metres of Maarten van der Weijden, who timed his move to perfection to finish in 1 hour 51min 51.6sec.

Davies' silver medal completes a fine performance in the open water event for Britain, coming just 24 hours after Keri-Anne Payne and Cassie Patten had won silver and bronze respectively in the women's race.

Former world champion Thomas Lurz was third as Davies, who was 1.5 seconds behind the winner, did enough to hold him off in the final push for the line.

With rain falling constantly, the conditions were perfect for open water swimming as the temperature dropped from the women's race the previous day.

Davies, who won an Olympic bronze medal in Athens four years ago in the 1500 metres, took the lead from the start, trying to establish an early lead before he was joined at the front by Greece's Spyridon Gianniotis, who was born in Liverpool.

The Welshman's pace strung out the field although Gianniotis managed to keep up, with Lurz keeping the pair in his sights.

With 34 minutes of the race gone, the Greek swimmer made a move to try and break away, opening a gap of more than five metres on Davies and the rest of the field only to be reeled in once again as Davies moved back to the front of the pack.

From there, Davies retained his position at the front of the lead pack until the start of the last of the four 2.5 kilometre laps, which saw Lurz and Australia's Ky Hurst increase the pressure.

Lurz moved through to the front at the beginning of the back straight and Russia's Dyatchin, the world champion, followed closely on this tail.

Davies remained close to the front, however, as the jockeying for position going into the final straight began in earnest.

Gianniotis and Italian Valerio Cleri surged towards the front as they approached the penultimate turn but Davies kicked again as the pace rose further.

Davies launched his attack just after the turn and looked to have the race sewn up, only for van der Weijden, who is in remission fleukemia,rom  to bridge the gap, helping to haul Lurz back onto the British swimmer's feet.

Van der Weijen's better ability to spot the finish played in his favour and the Dutchman powered clear to win having rarely featured at the front throughout the race.

Davies needed medical treatment at the end of the race but thankfully recovered after what he said was the toughest race of his life.

He said: "Its going to take a while to sink in because the last part I don't think I knew what was going on, I was delirious, I was all over the place and my head was spinning.

"I really had given it everything and I wanted it so bad.

"Give me a minute and I think I'll be over the moon because to get another medal in the Olympics is fantastic.

"I've only swam three open water races in my life.

"I'm still learning.

"I know I've made a lot of mistakes but I know I've given it everything which is all I wanted to do and to come off and have to get carried away by a stretcher is a bit mad but at least I know that I gave it everything and I've got something to show for it as well.

"Every time I do it I think its going to get a bit easier but it doesn't its still hard.

"I like to swim from the front but these guys were trying to make it as hard as possible for me, swimming all over me. I felt a bit violated to be honest.

"The last lap was a real real struggle.

"I'd wanted to swim the last straight fast but it was the whole last lap which was fast and the last bit was just like a blur.

"People were swimming all over me but I gave as good as I got."

Having recovered, Davies said that he did not want to do the event but by the time he got to the podium he had changed his mind and was already looking ahead to London 2012, when the event will be held in Hyde Park.

He said: "At the moment I don't want to do it again and I think if I said that to my coach now I may get away with it, but in four years time I'd really like to swim in London, where apparently the race will be in the Serpentine which will be a fantastic spectacle.

"I hope by then I'll be able to swim straight, learn all the tactics and get some meat on me to bounce them all off...maybe I'm too nice and need to get a bit rougher too."

"I'm only going to get better hopefully, if I keep training hard and still want it, get more experience.

"I hope to go one better in London in front of a home crowd in four years time."