Claims that champion jockey Kieren Fallon deliberately made a horse lose are "absolute rubbish", its trainer has told the Old Bailey.
Irish-based Mr Fallon denies the charges
Alan Jarvis, trainer of Right Answer, said the Irish rider was the "best jockey in the world".
Mr Jarvis said Mr Fallon, 42, gave "a perfect ride" and insisted he "never had any doubt" about his performance.
Six defendants, including Mr Fallon, deny conspiracy to defraud customers of betting exchange Betfair.
The scheme allegedly helped a syndicate, organised by businessman Miles Rodgers, to make money by laying bets on 27 horses which were to be deliberately stopped by their jockeys if they stood a chance of winning.
Right Answer came second in the race in question, held at York in July 2004.
Giving evidence for the prosecution, Mr Jarvis said he had been "more than satisfied" with Mr Fallon's performance on Right Answer.
"He gave a perfect ride, probably the best race the horse ever had."
Asked by John Kelsey-Fry QC, defending Mr Fallon, what he thought of the allegation involving his horse, Mr Jarvis said: "It's absolutely rubbish.
"I did not even know my horse was involved until I read about it in the paper.
"Until you ask me what riding instructions I had given him, how can you judge?"
Mr Jarvis said he had known the six-time champion jockey for many years and used him on a number of occasions.
"He is the best jockey in the world. I have never had any doubt about any horses he has ridden for me."
Last week, Australian racing expert Ray Murrihy said he would not have queried the York race either.
But he did claim Mr Fallon's performance during another race at Lingfield Park in March 2004 was "quite extraordinary".
The jury watched as Mr Fallon, riding Ballinger Ridge, built up a lead of eight lengths only to be caught on the line by another horse.
The defence earlier already admitted Mr Fallon made a "howler" on the horse, but denied any wrongdoing.
Mr Fallon, formerly of Newmarket, Cambridgeshire, but now of Tipperary, in the Irish Republic, Fergal Lynch, 29, of Boroughbridge, North Yorkshire, and Darren Williams, 29, of Leyburn, North Yorkshire, deny being involved in a conspiracy between December 2002 and August 2004.
Mr Rodgers, 38, of Silkstone, South Yorkshire, Shaun Lynch, 38, of Belfast, and Philip Sherkle, 42, of Tamworth, Staffordshire, also plead not guilty.
Mr Rodgers also denies concealing the proceeds of crime.
The trial continues.