Amid the celebrations of a record season, trainer Chris Waller has also had to deal with the more sombre side of racing.

Waller passed his previous Sydney total of 167-1/2 at Rosehill on Saturday when Pioneering gave him his second winner for the day and his 168th for 2015/16.

A little while later, Marenostro made the final tally 169 with victory in the $150,000 Listed Winter Challenge but in the same race stablemate Tales Of Grimm suffered a catastrophic hind leg injury and had to be euthanised.

"At first the injury didn't look too bad but once he cooled down it was obviously worse than we feared," Waller said.

"It has been a good day and a great season but there is the downside as well.

"These horses are all part of our family."

Winx is the undoubted star of the Waller stable and it was fitting her jockey Hugh Bowman was aboard Pioneering to bring up the record.

"I'm part of a team and my job is to ride the horses," Bowman said.

"I'm thankful for the opportunities I get from Chris.

"It's been my best season ever even though I didn't win the premiership.

"Obviously Winx has been the headline act for both of us and I'm privileged to ride her."

Winx won five Group One races during the season including the Cox Plate and Doncaster Mile, two of the toughest races on the calendar.

All up, Waller won 15 Group One events, nine more than his nearest rival, Melbourne Cup winning and Victorian premier trainer Darren Weir.

While Winx is at the top of the tree, Marenostro is among the others to play their part, bringing up the stable's 57th stakes win this season.

"He's very consistent - 1400 to a mile, heavy, soft good ground - it doesn't really matter," Waller said.

"It's a 52-week, 365 day a year business and all the horses are special.

"It's the last Saturday of the season but the staff will be there tomorrow and they'll be there on Monday for the start of the new season, so I'm proud for them."

Waller operates stables at Rosehill and Flemington, playing his part in Craig Williams' win in the Melbourne jockeys' premiership when Hursley won at Caulfield on Saturday.

That win meant Dwayne Dunn could not catch Williams and Waller said he was pleased to be a part of that.

"Craig is a great example for all young riders to see how hard work is rewarded," Waller said.

"He is someone to look up to."