Essex's Olympic mountain bike course has been deemed challenging enough by riders at the test event - although changes will be made for next year.
Some 5,000 spectators saw a selection of the world's best mountain bikers get their first taste of the venue in the grounds of Hadleigh Castle.
"For full-on effort this is probably the hardest course I've ever raced round," said Britain's Steven James.
France's two-time Olympic champion Julien Absalon won the maiden event to be held on the course - the Hadleigh Farm Mountain Bike International event.
The 5km circuit is largely man-made and features dramatic drops across imported boulders and tight twisting climbs. Unusually, it cuts across open ground with few wooded sections to obscure spectator views.
Critics have called the course too flat but Absalon believes it is a challenging track for the event.
"All the time you have turns, all the time you have rocks," Absalon said. "So you need to be focused all the time. It's difficult technically and also physically.
"The only problem is it's really difficult to pass on the track because most of the time you are on a single track."
Not that the Frenchman needed to overtake in Sunday's event - from the starting line he burst ahead of his rivals, creating a 20-second lead after the first of seven laps. He crossed the line in one hour, 31 minutes and 48 seconds, well ahead of Switzerland's Christoph Sauser and Austria's Karl Markt.
Britain put forward an inexperienced team of riders as the majority are preparing for an upcoming Olympic qualifier. Team GB's best hopes lay with Welsh national champion Lee Williams but, after crashing over his handlebars, he could only claim 20th place.
In the women's race, Canada's Catharine Pendrel won in 1.32:04, finishing ahead of Georgia Gould from the United States and France's Julie Bresset.
"I think people were holding back today but I know I can win on this course - it's tough, it's fun and it's fast," said Pendrel.
All of Britain's women were eliminated under the '80% rule' - any rider that is behind by more than 80% of the leader's lap time is taken out of the race - and one of them, Maxine Filby, found the course tricky but a good challenge.
"It is a really good course. When you practice it, it's not that bad but the faster you go the more technical it becomes. There has been unfounded criticism of the course but it is a hard course," she said.
The venue has clearly been chosen with the spectators in mind. Set within the grounds of 700-year-old Hadleigh Castle, the course snakes across uncovered meadows that melt into the Thames Estuary.
County Councillor Stephen Castle was an instrumental figure in taking the games to Essex, and he is delighted with how the venue has shaped up.
He said: "It's a great bowl, people can see two thirds of the course from pretty much anywhere they sit and you get great views of the castle".
Spectators are free to move between features that have been given names like "The Leap of Faith", "The Rabbithole" and "The Breathtaker".
London 2012 organisers, Locog, have confirmed that the course will see some amendments for next summer's race.
Riders have informally suggested widening and slowing down the circuit but Locog's director of sport, Debbie Jevans, will be balloting those who competed for their feedback.
"Every athlete has a questionnaire that they fill in. They give us that feedback and then there is a debrief to the international federation. As we have done with all our events, we then take that feedback and take the course to the next level," she said.