Grand warrior Buffering has defended his Winterbottom Stakes title while leading Sydney trainer Chris Waller has pulled off another coup with Grand Project winning the Railway Stakes at Ascot.

Trainer Robert Heathcote has flagged an international campaign for Queensland's star sprinter Buffering after his win in the first of the two $1 million Group One races in Perth on Saturday.

Buffering led all the way to win the Winterbottom (1200m) by a length from Waterman's Bay with Fast `N' Rocking another three-quarters of a length third.

"I got a call the other day from Dubai and I'm now keen to go there in March and then of course there's Royal Ascot," Heathcote told Sky Thoroughbred Central.

Now an eight-year-old, Buffering has already won the Group One Moir Stakes this season and, before his trip to Perth, finished a close fourth in the Darley Classic won by the Waller-trained Delectation.

Waller targeted the Railway Stakes (1600m) for Good Project who was having his first test in Group One company.

As Damian Browne did on Buffering, Craig Williams took Good Project straight to the front and the four-year-old strode to a comfortable two-length win over Messene.

"Chris said to trust the horse because this was the race they had targeted," Williams said.

"I was a little bit worried when he was under pressure but he was trained up to the minute.

"It's a great thrill to come here and win a race like this."

Good Project is owned by Macau businessman C C Lai who also races Delectation and Sydney Cup winner Grand Marshal, the victim of interference in the Melbourne Cup.

The Railway Stakes gave Waller his 10th Group One win for the season which is just 3-1/2 months old.