"I really could not have hoped to have done anything better than that at this stage of my career. I am delighted with it," Todd told journalists afterwards.
Mark Todd salutes the crowd after finishing his test on Gandalf. © Natasha Slavich
He said he was really pleased with Gandalf. "It's only a short time since I got the horse and he can't be any better.
"It's a little bit hard getting myself back into gear. Honestly, being here doesn't feel like being away at all. Eight years slipped by very quickly.
"It's been very, very hot and I'm absolutely drenched. I suppose seven minutes in the sauna wasn't that bad."
He was first to go today - and was also the very first competitor of the 29th Olympiad. "I didn't expect to be number one, it was just the luck of the draw," Todd said.
Todd bares all yesterday to walk the cross-country course. After three walks of the cross-country track, Todd said: "It's, big, all up and down and twisty and there are so many places to make a mistake. It's a very, very busy course and the horses will be mentally tired as well as physically tired." © Kit Houghton/FEI
Heelan Tompkins made a scratchy start and although Sugoi regained a measure of composure, their score of 55.6 ensures they have ground to make up on Monday's cross country. "My immediate reaction is I'm looking forward to the cross country," said Tompkins, who was the highest placed New Zealander at Athens four years ago when finishing seventh.
"After that test I'm looking forward to giving him a kick over the first fence."
Andrew Nicholson was the third member to ride for New Zealand. Andrew performed his test under lights in the second dressage session last night. Just before Nicholson and Lord Killinghurst entered the arena, a protestor was evicted from the stadium, the second of the day.
Tomorrow will be the turn of Joe Meyer and Snip and Caroline Powell and Lenamore.
Todd will also be first up in the cross-country: "I just don't know about how the horses will handle the heat and humidity, and being first to go, I won't have anything to guage it by. We've all got our horses as fit as we can and will hope for the best - some horses will handle it better than others."