He not only shares in the ownership of Adore Me with his daughter Mary and her husband Paul Kenny, but bred Have Faith In Me.
Roberts is also the principal of Woodlands Stud, so is therefore the man behind bringing champion stallion Bettors Delight to this part of the world, the sire of both those group one winners.
The vet who helped bring post-race swabbing to the country nearly 50 years go, Roberts' place in the history of New Zealand racing would have been guaranteed by that alone.
However, to have bred the winners of two of our greatest races on Cup Day gives the 90-year-old his own privately rewarding page in racing annals. "Dad was at home watching with Mum and she had tears in her eyes," said Roberts' daughter Mary.
"This is all about him and the horse because he would have loved to have been here but at his age it might have taken too much out of him.
"But this is about him and what he has been able to achieve in racing all coming together at once."
Purdon would have had Roberts in his mind as he gave a rare fist pump after the line, possibly still in shock at what had just unfolded.
Adore Me put herself in a race winning position by stepping well from her second-line draw, enabling her to settle midfield on the outer.
But that wasn't looking so rosy mid-race as Terror To Love, chasing his fourth straight Cup, worked to the lead and stared history in the eye.
Purdon played the waiting game until Christen Me, who galloped away, moved from last and he tagged on for the ride home but that soon hit a snag too as $200 chance Pemberton Shard got in between them, meaning Adore Me had to pull four wide down the back straight.
She sat there, outside Terror To Love and For A Reason, with Franco Nelson cruising in the passing lane at world record speed. What happened next should have been impossible.
When she should have been tiring, Adore Me found more and then more again, wearing the boys down to crown a new queen of harness racing.
The margin was only a half head but the win was a thing of raw beauty. Until you saw the time of 3:54.6, an unbelievable 1.8 seconds inside Changeover's world record.
Then it was no longer beautiful. It was brutal and ground-breaking, a mare racing like a stallion and dominating our greatest race.
Champion mares have won the Cup before - Armalight, Bonnies Chance, Blossom Lady and Mainland Banner - but none have beaten the boys up so badly with so little reason to be able to do so.
Already a millionaire mare, Adore Me is still only five and has the world at her hooves, with Sydney harness bosses having already invited her to the Miracle Mile in 17 days.
"We will wait to see how she comes through this before we make any decisions on that," said Purdon.
"It was a hard race and while the Miracle Mile is tempting there are plenty of other big races this season.
"But we don't have to make that decision just yet. We will enjoy this first."
Purdon's conveyor belt of champions is the busiest in harness racing but he rates Adore Me's win the best he has been involved in.
"She is a special mare and she beat great horses, which makes it that much more incredible."
Their stable heroine highlighted a scarcely believable day where their aptly named All Stars Stables trained seven winners from the nine races they had representatives, finishing close seconds in the other two.
They were almost the stars of the day. Almost.
Crowning the queen
• Adore Me smashed the world 3200m record in winning the New Zealand Trotting Cup.
• She headlined an unbelievable day for trainers Mark Purdon and Natalie Rasmussen.
• Auckland owner-breeder Charles Roberts celebrated the group one victories of Adore Me and Have Faith In Me from home.
