For the horse, an accident at Aintree in April 2008 had very nearly spelled the end of his racing career, while O'Brien had only recently returned to the saddle after breaking his right leg after a mishap in the paddock at Hereford back in June.

The Welsh National remains one of the most serious endurance events in the sport and after more than three-and-a-half miles on ground that needed to be inspected four times before racing could go ahead, only three-quarters of a length separated an exhausted Dream Alliance (20-1) from a closing Silver By Nature.

O'Brien said: "Amazing. I've only had about 12 rides since I came back. I had a couple of seconds and thirds and I thought I was doing something wrong, but this horse is a courageous animal.

"I broke my leg when a horse reared over on top of me and I was out for a couple of months, but this makes it all worthwhile. I love this game.

"When you're injured you're not in control, there's nothing you can do in that perspective. I'm just delighted I'm back now. It's a short career. I just enjoy every day of it.''

Dream Alliance is owned by the Alliance Partnership, a gathering of more than 20 friends from Cefn Fforest, a village that lies between Newport and Merthyr Tydfil.

The gelding made his comeback from injury over hurdles at the course last month and although he had lost his way over fences, he had still chased home Denman in the 2007 Hennessy.

One mistake at the last notwithstanding, Dream Alliance jumped very well, leading four from home and having just enough energy to haul himself over the line.

Trainer Philip Hobbs added: "It's like a dream come true for the whole lot of them. It's amazing really and he's aptly-named.

"He ran in a hurdle at Aintree and he cut right through his boot and his tendon.

"He had to go to Liverpool Veterinary Hospital but his injury was that bad, we were almost sure he wasn't going to run again. He came back into training quietly.

"Good job we didn't have another 20 yards to go. I was just a bit worried for a second.

"At his best, his form is very good but he's probably a bit better fresh, so we waited a long time from his first run over hurdles.

"He was a few pounds out of the Hennessy so we decided to miss that and this was the option. ''There's no reason why we shouldn't go to Aintree now, but we will savour this for the moment."

Dream Alliance was bred by syndicate member Brian Vokes, who also managed to breed a pigeon to win the equivalent prize for birds.

He can be backed at 33-1 with Coral and William Hill for the Grand National, while he is 25s with totesport.

It was frustrating for Silver By Nature's trainer Lucinda Russell, who had saddled Strong Resolve to take the same slot in 2004.

She said: "I'm gutted to be second but when you think about it, you have to be really pleased.

"I thought he got a dream ride through the race and he just didn't quite get there. The owner would like to go for the Scottish National but the ground will have dried up and I'd like to go for the Irish National instead.''

The 4-1 favourite Le Beau Bai stayed on for third, seven lengths behind Silver By Nature and just ahead of 2007 winner Miko De Beauchene.

The former's trainer Richard Lee said: "He didn't have the ideal preparation as we've had a lot of snow on the gallops, but I'm not going to use that as an excuse as he was fit enough.''

Sue Smith's Coe jumped superbly and led the field for much of the race but a mistake at the third last ended his hopes and he faded to finish sixth.

Yorkshire amateur Oliver Greenall, who rode Le Beau Bai, had earlier produced the Martin Harris-trained Magic Sky with a superbly timed run to land the coral.co.uk Handicap Chase at odds of 10/1.


Lexus chase set to try again today

The Lexus Chase has been rescheduled for today after fog caused yesterday's Leopardstown card to be abandoned after four races.

The Grade One feature was set to go off at 2.35pm but thick fog enveloped the track shortly before the start, forcing officials to delay the race until 3.20pm.

However, conditions did not improve sufficiently to race and the feature event has been switched to today's card and will be run as the fourth race.

The final two events scheduled for yesterday's card have been cancelled and will not be added to today's fixture, which will now start 30 minutes earlier than planned.