Trainer Michael Nolan admitted he almost sold out on Jumbo Prince mid-race before the Derby bound colt's win in the Toowoomba Guineas.

Jumbo Prince was the best backed horse at Saturday's meeting, shortening from $1.80 to $1.60 before beating Sky Limit ($4.80) by three-quarters of a length in the Guineas (1625m).

Nolan said Jumbo Prince would now back up in the Group Three Rough Habit Plate (2000m) at Doomben on Saturday and press on to the Group One Queensland Guineas (2200m) at Doomben on June 6.

"The seven day back-up into the Rough Habit Plate isn't ideal but he needs to get the runs into his legs," Nolan said.

"I am really proud of him. I thought on the home turn today he would struggle to run down the leader Sky Limit who gave us a real battle."

"But that is the type of horse he is. He beats good horses by small margins."

"I am just happy to be heading to the Queensland Derby with a live chance."

It completed a great Toowoomba feature day for the local trainer who earlier won with the promising Girl Command.

Trainer Gai Waterhouse is likely to press on with Sky Limit's winter campaign after his front running effort.