Cameron Hanley returned to the Grand Prix winner's podium in Germany after a near two-year absence caused by a freak accident to his knee that resulted in a total of 17 operations.
Competing at the five-star Riders' Tour Grand Prix in Wiesbaden, the Mayo-born rider and the 10-year-old gelding Antello Z collected €19,000 after seeing off a strong international challenge in the 12-horse second round.
He said: "It still hasn't really sunk in, it was such a fast jump-off. I just cut loose and went as fast as I could.
"It's amazing - a year ago I didn't know whether I'd ever ride again, never mind win a Grand Prix of this magnitude.
"I have a fantastic horse and he really proved his worth here today. This is my first Grand Prix win in four years, and I'm delighted."
Hanley added: "I originally found Antello Z when my brother Carl bought him at a local show as a seven-year-old and I rode him a year later, but when I sustained my injury Alex Duffy took him over, and then Michael Whitaker, who did a terrific job with him.
"When I returned to fitness, my new Swiss sponsors Eleonore Paschoud and Yves Bouv asked me to find a great Grand Prix horse, and there was no doubt in my mind which one - we bought him back, and he certainly delivered the goods this afternoon."
Hanley's knee injury occurred in May of 2011 while playing with his children in the garden of his home in Germany, where he is now based, and resulted in such severe complications that surgeons were at one stage highly sceptical that he might ever ride again.
Tipperary's Denis Lynch took 12th place in the Wiesbaden Grand Prix today, riding Lantinus.