Czabo ran down favourite Somehow in the final furlong to take Group Three honours in the Lodge Park Stud EBF Park Express Stakes at Naas.
Fourth in last season's Irish 1000 Guineas, the Mick Channon-trained filly showed she had benefited from a race at Saint-Cloud two weeks ago when sticking to her task in good style.
Graham Lee timed his challenge to perfection as Czabo (8-1) defeated the Aidan O'Brien-trained 7-4 favourite by half a length. Flying Fairies was third.
The trainer's son, Michael Channon junior, said: "We took her to Saint-Cloud a few weeks ago, but she was too free for the first half a mile and it was a complete wasted effort. But I just spoke to David Wachman (part-owner) and he said it was a great prep run taking her all the way to Paris.
"She's done it very nicely, and we had fitness on our side and that helped. We have a fairly moderate band of broodmares but he (Sixties Icon, sire) has improved them all.
"We wanted to get her going early as she had that Esher Cup form early last year in soft ground and ran well in the Guineas."
Former Grand National-winning jockey Lee recalled it was 25 years since he had his first ride at Naas.
He said: "I knew I had my first ride here. I checked and it was January 25, 1992 - 25 years ago.
"The ground is very holding but she's got big old feet and she coped with it well."