The 19-year-old rode the British-bred Kannan mare Molly Malone V to the fastest time of the morning (77.01sec) in this first round against the clock in which both individual and team riders compete.
“It all went according to the plan, which was to get a sound round,” said Bertram, a recent winner of the grand prix in Dublin. “Molly Malone just took everything in her stride. We had some tight turns, but she can handle it and we got the measure right today.”
Bertram is based in Germany with Marcus Ehning, who currently sits in 12th place with Cornado NRW. He added: “My student is in the lead, so it’s special.”
75 of the 153 riders have jumped so far and France’s Penelope Leprevost (Flora De Mariposa) holds second place in 77.82sec with Peder Fredricson of Sweden third on H&M Sibon (78.96sec).
The course has resulted in a surprising number of problems with eight eliminations including Brazil’s pathfinder Doda De Miranda, who fell when AD Rahmannshof’s Bogeno refused at a vertical.
Team GB’s Michael Whitaker (Viking) is best of the British, lying 18th, with Joe Clee (Utamaro D’Ecaussines) in 21st position individually.
“I’m very proud to be here,” said Joe, who produced a great clear in 85.49sec with the “fresh” but slightly spooky 10-year-old stallion.
Michael added: “It was a solid start. My horse did everything I wanted him to do so it’s been good for the team.”
Don’t miss the full report on all the showjumping action from WEG in H&H next week, out Thursday, 11 September.