Champion jockey Robert Thompson had no doubt the favourite Darci Magic threw away a win in the $50,000 Grafton Motor Group South Grafton Cup on Sunday.

The Bede Murray-trained gelding finished a head second to bold frontrunner Kurtley, trained by Leon Davies at Tamworth.

Darci Magic was well back on straightening for the run home with Thompson giving the four-year-old plenty of room on the outside of the field.

However, just as Darci Magic looked like he would gobble up Kurtley in the last 100m the gelding refused to run on a straight course. Thompson did his level best to straighten Darci Magic but the bird had flown.

"It cost him the race no doubt," said Thompson, who was shooting for his sixth win in the event.

For Davies the win was most pleasing and a credit to his ability as a trainer to revitalize the five-year-old gelding.

"This is his fourth year in a row coming to Grafton for the carnival," Davies said. "He ran in the two-year-old race, won the Guineas as a three-year-old and ran in the Grafton Cup last year. He loves the place.

"If he didn't win today he was going to run in the Birdsville Cup. Obviously that's off the cards now.

"He's been a very honest horse. I had to run him in all those races in Brisbane to try and get his rating down.

"He was well in at the weights and it was a great ride by Darren Jones."

Tamworth-based Jones rated Kurtley superbly in front.

"I had to use him up a bit from the gates," Jones said. "If I took a sit I would have been three wide so I let him stride forward. He came back under me beautifully. We had a lovely run.

"The trainer said if I could hold him up until the last 600 metres, he'd finish strongly. He did just that. It was a good win."