Nina Carberry was described as "brilliant" by connections of Forest Gunner ahead of the amateur's debut ride on the horse in the Totesport Becher Handicap Chase at Aintree.
Carberry, whose brother Paul won the Grand National on Bobbyjo in 1999, takes over tomorrow from the now-retired Carrie Ford on the 11-year-old in a race over the big fences.
Ford, wife of the horse's trainer Richard, famously finished fifth on Forest Gunner behind Hedgehunter in the John Smith's Grand National in April.
"I think Nina is brilliant," Ford said. "Michael Hourigan paid her the biggest compliment anyone could in the Limerick report from Sunday when he said there's no difference between her and Paul, and that about sums it up."
A bold show is expected from Forest Gunner, who has a good record over the Grand National course having landed the Fox Hunters' in 2004 and the last season's Grand Sefton Chase.
"Forest Gunner is in great form at the moment and if he remains in one piece we are very much looking forward to Sunday," Ford continued.
"Touch wood Richard is very happy with the way he has trained and his programme is on target so far. It's just nerve-wracking over the last few days that nothing silly happens.
"He stayed with us for his summer holiday and he's had a good break."