Cambridge trainer Roger James had the perfect entree to Saturday's Caulfield Cup when Zonza scored an uncomplicated win in yesterday's Snowhite Classic on the same track.
"Well, I thought she'd be competitive in a race like this after her overall form," said James.
"She's been first or second in 10 of her 12 starts before this."
James has Silent Achiever in Saturday's Caulfield Cup. The mare, a Derby winner, has drawn well at five for what is the biggest test of her career and bookies have tightened her quote into $7 with Royal Ascent.
Zonza earned her trip to the Melbourne spring carnival with her first-up Te Rapa victory.
Yesterday's winning jockey Damien Oliver was suitably impressed. "She was very solid once she got going and got the front in the home straight."
Guelph has confirmed her status as the dominant 3-year-old filly in the country with victory in the Thousand Guineas at Caulfield.
Her win capped a marvellous week for Darley, which celebrated a big race double on Saturday with Long John in the Caulfield Guineas and Complacent in the Spring Champion Stakes at Randwick.
Kerrin McEvoy made a surprise move on Guelph shortly after the start of the Thousand Guineas (1600m) by taking her to the front in the small field of nine.
"When she began well I thought, 'stuff it, I'll take the race by the scruff of the neck'," McEvoy said.
Best known as a backmarker, Guelph showed another string to her bow by dictating the speed.
She comfortably accounted for runner-up May's Dream, who momentarily looked as though she might challenge the Peter Snowden-trained favourite in the straight but couldn't match Guelph over the final stages.
"When that second horse came to her she kicked and if anything else had of come to her she would have kicked again," Snowden said.
Gregers did best of the rest to finish third. The Darley team will decide in the coming days whether Guelph will press on to the Cox Plate on Saturday week or be spelled.
- Additional reporting AAP