Tough mare My Dimantine is in line to give her trainer Brian Smith another Newcastle Cup win after returning to the winners circle from a two years drought on Saturday.

My Dimantine ($10) was having her first start since finishing second in the Queensland Cup over 3200m on July 15 when she stormed home to win the Open Handicap (1615m) at Doomben.

She had not won since November 2015 and had only one win from 24 pervious starts on a good track.

But statistics meant nothing to Smith who has the mare for his friend John Wheeler, who trained the champion Rough Habit.

"She was so consistent during the winter picking up prize money with seconds in races such as the Caloundra Cup and Queensland Cup," Smith said.

"I put her in the paddock and she was bucking her brand off. John said give her 10 days and then head her to the Newcastle Cup.

"And no I haven't nominated her for the Melbourne Cup."

Smith won the 2006 Newcastle Cup with Bikie Tin Blues and has had several runners in the race over the years.

The Newcastle Cup (2300m) will be run on September 15.

The favourite Sheiswhatsheis ($2.70) kicked clear in the straight but was run down by My Diamantine in the final 100m.

Trainer Stuart Kendrick admitted he had a major decision to make after his well bred three-year-old Rancho Montoya ($4.60) won the Class 3 Plate (1615m) in impressive style.

"On one hand Rancho Montoya shows a lot of potential and he won today like a horse who is going to be a top stayer _ he just ground them into the turf," Kendrick said.

"He is entered for some good races in the south such as the Caulfield Guineas. But it is his first real campaign and we have the Sydney autumn and Brisbane winter as a back up."

Rancho Montoya is by former top side High Chaparral out of the Group One winning mare Isolda.