Chris Waller's quest to break his own metropolitan training record will go down to the wire.

Sydney's premier trainer notched two more victories for the 2015/16 season at Canterbury on Wednesday thanks to late season two-year-old Overstep and English import Quick Defence.

Those horses took Waller's season tally to 166, two clear wins shy of the 167-1/2 he set in 2012/13.

Overstep ($7) won at her first start for Waller since being transferred from suspended trainer Peter Moody.

The filly overcame a tough field of two-year-olds to win her maiden, including second-placed Star Of Monsoon ($3.50 fav), a horse trainer Gerald Ryan had included in his Caulfield Guineas calculations.

"My confidence was dented by the strength of today's race," Waller said.

"It was a very strong two-year-old race as they normally are in Sydney."

The John Thompson-trained Fabvier ($9) finished third.

Waller said Moody thought highly of Overstep.

"It's always good to get a bit of fitness into these horses before the better ones come back," Waller said.

"Hopefully we can find a Saturday race again before they all come back charging with their medals on."

Quick Defence won for the first time on Australian soil, coasting to a 3-1/2 length win in the 1550m benchmark 72 race.

"I said to the owners just before the race he won't be racing on Wednesdays for long," Waller said.

Jockey Hugh Bowman rode Quick Defence and More Than Fabulous to win on Wednesday, but the victories were soured when he received a careless riding suspension for his ride on Ziggy Willie in the fifth race.

Bowman, who stewards found to have failed to prevent Ziggy Willie from shifting in during the final 50m, is free to ride at Rosehill on Saturday but will miss the chance to ride in the Group Two Missile Stakes the following week.

His suspension starts on August 4 and ends on August 11.