Not sure what to do, Concert Hall slid to a halt but not quickly enough and hit the fence, flipping over it and on to her back.
She got back up, now off the actual racing surface, and galloped away from the raceway property and into a neighbouring children's playground, across a busy road then down a bank and ended up in a park around 600m from the race track.
She was chased the entire way by Clerk of the Course Linda Wheeler, the wife of local trainer John Wheeler, who jumped two fences on her own horse to eventually capture Concert Hall in the park.
The Clerk of the Course is a skilled horseperson employed at all race meetings to help with horse safety and catch horses on the rare occasions they escape from their riders.
Remarkably, apart from losing some skin off all four legs and bruising which is likely to come out in the next few days, Concert Hall was fine today.
"It could have been so much worse," explains James.
"The road she crossed had she taken a different turn she would have ended up in the centre of the city and I hate to think what would have happened.
"So while it was very scary for us we were really lucky."
Wellwood outpaced his more senior training partner in the chase after their stable star but says the credit must go to Wheeler.
"Linda was fearless chasing after her and keeping her in sight and she told us later it was actually her first catch of a horse as Clerk of the Course, and it was hundreds of metres away from the track."
Wellwood says while the incident was scary for the stable and racegoers it was just as confusing for others who had a fully-saddled racehorse burst into their Saturday afternoon.
"One of our owners got a Snapchat from a friend who was at the playground with her kids saying "you won't believe this, there is a racehorse here."
Concert Hall is the pride and joy of breeder-owner Joan Egan and has developed into one of New Zealand's elite racehorses and James says she will be good to return to the races in a few weeks.
"She really hasn't done herself much harm. But we were so, so lucky."