It was a triumphant return for Bluetooth OLD after an extended break from competition; Germany edged Portugal and the Netherlands in an 8-team roster.
The British rider led the way as all combinations met the minimum score requirement of 60% and move on to Saturday's Freestyle Final.
The rider cruised to his first-ever Longines Global Champions Tour Grand Prix Victory to the delight of home-country fans in Mexico City.
Canada's Denielle Gallagher and Come Back De Massa place 3rd as the venue hosts its third international dressage competition of the year.
The 12 weeks of competition at Wellington International will feature the season finale $750,000 Rolex Grand Prix at the end of March.
The Holiday & Horses CSI4* week at Wellington International concluded with the US rider scoring in the feature Grand Prix on Sunday.
The FEI dressage committee will 'encourage' organisers to run special classes up to CDI3* for athletes who wish to use a snaffle instead of a double bridle.
The American won the highlight class of the inaugural CSI3* event in New York's Hudson Valley out of a starting field of 45.
Ramzy Al Duhami is 'Untouchable' in Saturday's World Cup, while the Saudi team took Sunday's Nations Cup as the Morocco Royal Tour continues.
A roundup of show jumping action at the Major League Show Jumping Ottawa at Wesley Clover Parks this past weekend.