Sally Taylor was working in a Coffs Harbour shop selling mobile phones when she made a career change to train horses.

The move has paid quick dividends with Rednav, a horse part-owned by her old boss at the shop, winning the $160,000 Listed Grafton Cup on Thursday.

"It's absolutely amazing - the best feeling I've ever experienced," Taylor told Sky Thoroughbred Central.

"I cannot believe I'm standing here right now."

Despite winning the Grafton Cup Prelude at his last start, Rednav started at $26 and paid more than $50 on some totes.

The five-year-old let down strongly in the straight to narrowly overcome All Clear ($12) and Jumbo Prince ($5) in the 2350m feature.

Taylor's old boss Peter Wood is a part-owner in Rednav and races a handful of the other horses in Taylor's stable.

"She came up to me one day and said `I don't mind the phone shop I'm working for, and I work for your phone shop, but I want to be able to ride horses as well'," Wood said.

"I said you can ride my horses and then after that you can call in and sell a few phones, but I don't see her in the phone shop anymore."

Taylor took her trainer's licence out in February and Wood set the bar high for her, asking for a 20 per cent winning strike rate - a level she has eclipsed by scoring six wins from 28 starters.

The Cup win was the biggest success of country jockey Peter Graham's career.

"I've got to pinch myself," Graham said.

"I've ridden winners everywhere but not at this level or in the city - I hardly ever get there.

"That was a real buzz."

Graham said Rednav's win in the Prelude gave him a rough hope, but thought he would be outclassed against Sydney-trained horses.

"Realistically I thought (he was) just another country horse whacking away against these good horses," Graham said.

"One for the good guys I suppose?"