Scone trainer Rod Northam and champion jockey Robert Thompson combine with Myamira in the $50,000 South Grafton Cup on Sunday in what they hope will be the first of a feature-race treble during the famous country racing carnival.

They will also combine with Big Money in Wednesday's $150,000 Ramornie Handicap and Husswick in the $42,000 Grafton Guineas (1600m) on the same day.

Thompson, 56, has an enviable record in the South Grafton Cup having won it four times.

His previous winners were Brigalow (1984), Retford (1988), Shoemaker (2002) and Laogan (2008).

Myamira, a six-time winning mare, is coming off an excellent last start four-length 10th in the Group One Tatt's Tiara at Eagle Farm on June 21.

Myamira had little luck, being posted wide throughout.

Before that she resumed from a 112-day spell with a length third to Seaside in the Group Three Dark Jewel at Scone on May 17 then was sixth to Cosmic Endeavour in the Group Two Dane Ripper at Eagle Farm on June 7.

"She's done really well since the Tiara," Northam said. "She's feeling well and has worked well. There are no problems.

"I've just kept her ticking over. She's probably been looking for the mile at her past two starts.

"I thought her last run was probably the best of her career.

"She sat five deep. Robert (Thompson) said she was entitled to lie down in the straight after the hard run but she just kept coming."

Myamira's task has been made slightly easier with the early scratching of topweight Hi Son.