The 16-year-old gelding clipped himself, resulting in an injury to a check ligament, at the Spruce Meadows National tournament on Sunday.
Mark and Tara Rein's Rome Gladiators team of Nina Mallevaey, Zoe Conter and Shane Breen finished in third spot.
The Canadian rode Chacco Kid in Sec. A of the split class, and Jacqueline Steffens was 9th riding Freaky Liefhebber.
The French rider claimed victory aboard Vivaldi des Meneaux, while earlier in the week Canada's Eric Lamaze placed second with Chacco Kid.
The Canadian steered Chacco Kid to 4th place in the Du Grand Chesall during the Hubside Spring Tour in St. Tropez.
The Irishman took the $137,000 Grand Prix CSI3* with Great-Tikila J; top Canadian was Eric Lamaze with Chacco Kid in 4th spot.
Lamaze is back in Florida and got right down to business, winning the $37,000 Douglas Elliman 1.45m CSI3* over Michel Vaillancourt's course.
Canadians Eric Lamaze and Tiffany Foster place 5-6 in the class, while Rachel Cornacchia grabs 2nd place in $50,000 grand prix.
The first international grand prix of the 2021 WEF circuit ended in a win for Madden, with two Canadians in the top ten.
“The horses are fresh ... They feel like they got a year younger with a year off," said the Olympic gold medalist following his win.