The Olympic Champion had 15 top-ten finishes this season, but a Challenge Cup victory had eluded him; Canada's Erynn Ballard 8th with Dior.
The Egyptian rider piloted Evergate Stables' mare who is "such a trier" as the WEF winter tournaments head into the home stretch.
The Irish rider's fairly new partnership with the big-strided and sometimes "misunderstood" mare is steadily improving in the five-star ranks.
The US rider piloted the good mare and "alpha horse" Greya to another massive payday under the ‘Saturday Night Lights’ at WEF.
Canadian Nicole Walker and Atout des Trambles were edged by Jessica Springsteen by just one-tenth of a second in the large class of 68.
The victory came aboard the mare Greya, deflecting a strong challenge from Christian Kukuk and his Olympic gold medal partner Checker 47.
This week the Belgian pulled out Katanga V/H Dingeshof, a speedy 15-year-old mare, for the first time this season.
The German rider won the lion's share of the $215,000 purse in the MARS Equestrian CSI4* Grand Prix on the grass field.
The Colombian bested a large field representing 13 nations aboard Iron Maiden to edge Shane Sweetnam by more than two seconds in the jumpoff.
The grand finale of Saturday Night Lights saw the German rider aboard Checker 47 edge two American rivals in his Wellington debut.