Moscow Flyer has been retired after finishing fifth in the Queen Mother Champion Chase at Cheltenham.
The 12-year-old was trying for a third win in the two-mile showpiece after enjoying success in 2003 and 2005 but he bows out after failing to win any of his four starts this term.
Trainer Jessica Harrington told Channel 4 Racing: "I'm delighted he retires in one piece, that we go on and he retired here at Cheltenham where he had his finest hours.
"Barry (Geraghty) said he just got out of it a bit today but he was always just niggling at him and he was always under pressure instead of travelling. He doesn't like being out in the field, only for a couple of hours a day so we will see what we do now."
Moscow Flyer won 26 of his 44 starts under Rules and amassed more than £1million in win and place prize money. As well as his two Champion Chase wins, Moscow Flyer also won the 2002 Irish Independent Arkle Challenge Trophy.
However, owner Brian Kearney believes his narrow win over Azertyuiop and Well Chief in a thrilling battle for last year's Tingle Creek Trophy the pinnacle of his career.
He said: "The horse will be retired. I think you get into a bit of a dream watching it but there was a very frightening moment today when it seemed he may be brought down.
"He got through that and probably lost a bit of pace behind the others but I think coming down the hill you could see he wasn't going to make it. I think the Tingle Creek with Well Chief and Azertyuiop would be the highlight."
Geraghty said: "I had a brilliant time with him and he was a great leg up for my career."