Two horses with family ties to Group One winners landed important midweek victories at a rescheduled Canterbury meeting on Thursday.

The superbly bred Defender, by Redoute's Choice out of outstanding race mare Alinghi, broke her maiden with a determined win in the Hyland Race Colours Plate.

Not to be outdone, former New Zealander Bonete, a three-quarter sister to Terravista, posted her first win in Australia when she outpaced odds-on favourite Najoom in the Cal Rei Handicap.

Ridden by Tommy Berry, Defender was having her second start and her victory vindicated a decision to roll the dice on a heavy track.

"We were a little bit concerned coming here today with the wet track, as were most people, but everybody knows Canterbury plays pretty fair," co-trainer Michael Hawkes said.

"We gave her one run last time in and she probably just wasn't really there yet. She's come back in a lot bigger and stronger this time."

Joe Pride's decision to put blinkers on Bonete proved the right move with the mare controlling the race from the front to land a Sydney win that will enhance her residual value.

"She's a three-quarter relation to Terravista so she's got a bit of pedigree behind her," Pride said.

"She was sent over here to see if she could make a mark on Australian racetracks and she's done that today."

The afternoon wasn't as kind to Blake Shinn whose riding pants came undone shortly after the start of the first race.

The further the horses went, the further down they crept, leaving Shinn somewhat exposed as he passed the finishing line on runner-up Miss Royale.

Ever the professional, Shinn didn't shirk his task despite the wardrobe malfunction and failed by a long head to reel in Defender.

The incident provided light banter on course but the biggest talking point was the performance of the Canterbury track which, in spite of the torrential rain this week, was upgraded from heavy to soft after the fourth race.

"Considering 24 hours ago it was underwater due to a blocked drain in the back straight, its recuperative powers of drainage are amazing," steward Greg Rudolph said.

The meeting was postponed from Wednesday due to the wild weather conditions.