The German was near unbeatable as he recorded a pair of wins on Mousse and Domingo on Wednesday before claiming the Grand Prix a day later with a double clear atop Cornet d'Amour.
Britain's Ben Maher was second, two seconds behind Deusser, who had earlier come in third in the preparatory class for the Grand Prix.
The signs were already good for Deusser during the warm-up week in Florida, when he took third place in the Nations Cup team event and 16th in the Grand Prix after scoring four points.
The latest results go some way to proving Deusser, who was close to the top of the jumping world with Air Jordan Z not so long ago, is getting back to where he belongs.
- Sports & Recreation