Nicholson is currently in 14th place, Jonathan Paget and Clifton Promise are 16th, Johnstone and Orient Express are 28th, Mark Todd and Grass Valley are 33rd, and Caroline Powell and Mac Macdonald are 63rd.
Nicholson was very happy with his chestnut gelding. "He tries very hard and didn't seem phased by the occasion at all," he said.
The only little hiccup in his test were his flying changes, and Nicholson had no doubt that once they sorted that Nereo would be "very smart at dressage".
"He was very focused in there."
Nicholson is looking forward to the cross country. "It's a very good fair course that's difficult to the end," he said. "You can't get three quarters of the way around and start scorching for home, you need a nice rhythm to the end."
He had no doubt in his horse who was very capable of dealing to all challenges posed and was a good, fast cross-country horse. He felt the course had many more vertical fences than a lot of riders were used to, and it was a style that he felt paved the way for the future.
"It's easier that jumping those big wide boxes," he said. "You've got to respect these jumps and ride them properly."
That the course contained no surprises for the horses was a huge improvement on many other courses they rode.
"Some times the horses can't see element B until they're a stride before, which is quite unfair," he said. "With this course, if you ride it properly there is plenty of time to see and the horses have a good chance."
The undulating terrain contributed to the challenge and meant it was "pretty full on" right to the end.
"It's a smooth ride but one slowed by the twisty and turny nature of the course. I plan to go clear and inside time - by about a second," he said when asked about the team plans for the course.
All the Kiwi riders would receive vital feedback from Mark Todd on NZB Grass Valley who is first out. Nicholson will once again anchor the team, with Todd, Johnston and Caroline Powell on Mac MacDonald ahead of him.
"We'll change the game plan if we need to after we talk to Mark."
Meanwhile Johnstone, who at 23 was the youngest in the team, said he was enjoying every aspect of being at his first world games.
He was pleased with his dressage and said while he felt quite calm riding into the arena, he had a sudden flutter of nerves part way through the test.
Orient Express has been bothered by the flies in Kentucky, and today was no different.
Johnstone says he's thoroughly enjoyed watching plenty of top class dressage and figures he may just have become gold medalist Edward Gal's stalker. He's been watching closely to see what he can learn from him.
Germany is leading the eventing teams with some solid performances and sitting on a score of 114.3 from their best three results, with Great Britain second on 128.5, Sweden third on 131.2 and New Zealand in sixth spot on 138.3.
Leading individually is Michael Jung (Germany) on La Biosthetique-Sam FBW on 33 points, second is Stefano Brecciaroli (Italy) on Apollo van de Wendi Kurt Hoeve on 35.5 and Simone Deitermann (Germany) in third spot with 36 on Free Easy NRW.
The eventing culminates with the showjumping on Sunday.
Individual - 1, La Biostethique Sam (M Jung) GER 33.0; 2, Apollo Van de Wendi Kur Hoeve (Stefano Brecciaroli) ITA 35.50; 3, Free Easy NRW (Simone Dietermann) GER 36.00; 4, Gazelle de la Brasserie CH (Karin Donckers) BEL 38.0; 5, Courageous Comet (Rebecca Holder) USA 39.30; 6, Mister Pooh (Niklas Lindback) SWE 39.50; 7, Euroridings Butts Leon (Andreas Dibowski) GER 40.00; 8, Miners Frolic (Kristina Cook) GBR 40.30; 9, Mr Medicott (Frank Ostholt) GER 40.70; 10, Happy Times (Sam Griffiths) 40.80.
New Zealand dressage scores, team: Mark Todd, NZB Grass Valley 48.5, Caroline Powell, Mac MacDonald 57.2, Clarke Johnstone (Outram/Matangi) Orient Express 46.5, Andrew Nicholson, Nereo 43.3. Individual: Jonathan Paget (Muriwai) Clifton Promise 44.2.