David Wachman expressed satisfaction that his faith in Winter was vindicated with a Classic victory at Newmarket earlier in the month.
Wachman used to trained the Galileo filly until his retirement at the end of last season, with Aidan O'Brien now in control.
Winter made a significant impact for her new trainer as she surged two lengths clear in the 2000 Guineas and is now set to go for the big-race double in the Irish equivalent at the Curragh on Sunday.
Wachman told the Irish Times: "I'm delighted everything has worked out so well for everyone.
"I always believed Winter was a very high-class filly and I'm delighted it's come to fruition. Aidan has done a great job with her."
Wachman is adamant another former inmate, Rekindling, can still have a big say in the Investec Derby at Epsom on Saturday week.
The High Chaparral colt looked the part when winning the Ballysax Stakes at Leopardstown on his first start for Joseph O'Brien in April.
Rekindling will, though, have a bit to prove if he runs in the premier Classic after he was comprehensively defeated by fellow Epsom hope Permian in the Dante Stakes at York.
Wachman said: "He was always a good enough horse and he won his maiden well. But my horses were in and out last year and a bit under the weather.
"The Derby is open and he has some chance, I'm sure. He ran okay in the Dante."
