The New Zealand rider and Jarillo dashed French hopes, while British rider Tom Jackson leapt 29 places up the leaderboard during the weekend.
A selfless volunteer and hard-working official, Renz was one of Canadian eventing's most passionate supporters.
EC has released the requirements for jumping, para-dressage, dressage and eventing to be considered for this important Olympic qualifier.
Several Canadians helped showcase six- and seven-year-old horses at the FEI WBFSH Eventing World Breeding Championship.
The Swiss rider rode the "unbelievable" mare Cartania to a final score of 28.7; Isabelle Bosley and Conner clinch top spot in the CCI3*-L.
The NZ rider has a rail in hand ahead of Felix Vogg (SUI) heading into Sunday's show jumping; Isabelle Bosley and Conner top the CCI3*-L.
Canadian singles driver Kelly Bruder regains top spot; plus riders who continue to have a stranglehold on first place in the other disciplines.
Athletes from seven nations including Canada will compete across the 3*/5* divisions at Fair Hill, October 16-19.
Eventing High Performance will award Country Yucca grants for up to four recipients to cover travel expenses within North America or overseas.
The second day of dressage at the FEI Eventing European Championship at Blenheim Palace saw FischerChipmunk log a score of 18.3.