Jumps racing lost its great champion yesterday when Best Mate died of a suspected heart attack on his eagerly-awaited return to racecourse action at Exeter.

Paul Carberry was the rider aboard the triple Cheltenham Gold Cup winner in the William Hill Haldon Gold Cup and while the pair travelled smoothly during the first half of the race, he started to nudge the horse on as the leaders moved clear.

Carberry began to ease the Henrietta Knight-trained ten-year-old in the home straight, eventually pulling him up, and screens were swiftly erected around him.

Knight's husband and assistant Terry Biddlecombe said: ''Paul is a good jockey and he knew something was wrong. The only consolation is it was pretty instantaneous and he wouldn't have felt any pain.''

Best Mate had been forced to miss an attempt at a fourth consecutive Gold Cup when he burst a blood vessel in his final workout before the big race.

He had not raced in public since finishing second in Ireland last Christmas, but connections had reported all had been well with his preparations for his reappearance.

Knight said: ''I have ridden a horse before who suffered a heart attack while I was on board and I have to say this looks reminiscent of that. The legs go, they wobble and then they go down.

''I was actually on the track where he came down and I was the first one there. I knew immediately he had died.

''As I saw him go down I knew I was seeing a dead horse and I just wanted it to be over as quickly as possible.''

She continued: ''I am very proud of him - he looked an absolute picture today on a course he loved. He was a joy to work with and a privilege to train.

''Obviously I am very sorry for the jockey and for Mr and Mrs Lewis (owners), who are distraught.

''It is probably harder for a lot of people watching the race than it is for Terry and I, as we are more used to this sort of thing happening.

''He was a very, very popular horse with a tremendous following and now there is a big vacuum.

''Even this morning he was getting good luck cards in the post - but I suppose we have all got to go one day and at least he didn't do anything terrible like fall or break a leg.

''I suppose it is a relief he will never lose his unbeaten record in the Gold Cup now. I was dreading him going to Cheltenham and being beaten one day.

''It seems strange to think a few minutes ago I was watching him walk down to the start. He looked an absolute picture and I was so proud of him.

''He put my stable on the map and achieved something in winning three Gold Cups that probably none of us will ever see again.

''We will all miss him very much.''

Best Mate was partnered in 18 of his 22 races by Jim Culloty, who said: ''The fact he was as good as he was, as honest as he was, and as consistent as he was, was why the public came to love him and deservedly so.

''I gave up riding a few months ago and my one regret was that I wasn't going to be able to ride Best Mate any more."