But a maturing McNab didn't panic and was aided by first the hot tempo and secondly being able in mid-race to find the back of favourite Endless Drama, who got trapped three wide and was no hope a long way from home.
Melody Belle was gifted a perfect gap when Endless Drama crabbed around the bend at the top of the straight and then set her sights on the leaders. From that moment on it wasn't a fair fight, a great horse mowing down very good ones.
After her Tarzino defence it is easy to feel the Triple Crown, consisting of the Windsor Park Plate (1600m) on September 21 and the Livamol Classic (2040m) on October 5, is at Melody's mercy.
But there is a reason no horse has won the Triple Crown at the Bay and Richards knows that last leg will present a vastly different challenge to the far more similar first two legs.
"The way she quickened was quite exciting and maybe tells us she has other racing patterns available to her rather than racing handy most of the time.
"So all being well the mile next start should suit and if we can draw well then she has to be hard to beat.
"So the Triple Crown is the aim but the last leg won't be easy.
"By then she would have had to go to Hastings three times, which is not a small trip, and she will be up to the 2040m.
"We all know she won at 2000m at Ellerslie last season and being older and stronger should be able to handle it but she still might be racing horses in that last race who are better suited to the 2040m.
"So we have a fair way to go yet and after we get through Hawke's Bay we can think about exactly what suits best in Australia."
It is hard to make a case any of those who finished behind Melody Belle beating her in the Windsor Park, though there is likely to be some new blood enter the fray. Four-year-olds Vigor Winner and Cutadeel raced up to their reputations to beat older horses when fresh-up on Saturday and both are pencilled in for the second leg of the Crown, albeit not ideally suited at weight-for-age.
And impressive Ruakaka winner Hello It's Me will also head to the Windsor Park Plate for trainers Chris Gibbs and Michelle Bradley.
"I think she is still a bit under-rated and she can go to the last two legs down at Hastings," says Gibbs.
But their stable star Danzdanzdance, who was good without dazzling when fifth behind Melody Belle, definitely won't be back for the Windsor Park.
"She has two options, here or Australia and we won't make any decisions on that until we see how she comes through things and talk to the owners," adds Gibbs.
"But even if she stays in New Zealand for the next month she definitely won't go to the Windsor Park Plate. If we keep her here her next start will be in the Livamol."
Another high-class mare who definitely won't be in the Windsor Park Plate in Melody Belle's stablemate Avantage, who had to settle for second to Hello It's Me after her return race didn't go to plan at Ruakaka.
"We have plenty of options with her but the Windsor Park isn't one of them," says Richards.
One down, two to go
• Melody Belle defended her title in the Tarzino Trophy.
• The next leg of the Hawke's Bay Triple Crown is the Windsor Park Plate on September 21.
• No horse has ever won the Triple Crown which will culminate with the Livamol Classic on October 5.
