He was supremely confident before the BMW Hong Kong Derby (2,000m) but there was still an element of disbelief among the euphoria as trainer Dennis Yip Chor-hong celebrated the greatest moment of his career at Sha Tin on Sunday.

Unraced in Hong Kong until three weeks ago, Massive Sovereign produced one of the great Derby victories to give Yip a feeling that surpassed even his triumph in the 2012-13 trainers’ premiership.

“I’m very happy, it’s amazing for my life. What a memory,” said the 56-year-old. “It’s very exciting. I think the Derby for me is more important than the championship because this race is my [biggest] winner.”

While Yip boasts well over 800 victories in a career dating back to 2002, he’s never won a Group One race. While the Derby might not officially be a Group One, in Yip’s mind it may as well be.

“Group Two, Group Three I’ve got already, the championship I’ve got already, but this one for my life is the big one,” said Yip, who has never gone close to matching the output of his premiership season and even received a strike last season for failing to meet the Jockey Club’s trainers’ benchmark.

While Yip admits he had his heart in his mouth as Massive Sovereign cornered for home near the back of the field with runaway leader Ka Ying Generation still striding freely, he took comfort in the knowledge that it was Zac Purton in the saddle.

“The last 200m I was very nervous but I rely on Zac. He is the champion jockey in Hong Kong and everything was good with the horse. Every time after the gallop he told me ‘nice horse, gentle. I like him a lot’. Every time,” Yip said after Massive Sovereign mowed down the leader and held off Galaxy Patch by a neck.

Purton made mention of how special it was to win the Derby with Yip after the success they’ve had – well over 100 winners including plenty during the trainer’s championship season – and the handler was just thrilled to have a horse good enough to pique the interest of the six-time champion jockey.

“Everybody knows he’s a really good jockey and it’s not easy to get him to ride your horse. But this horse, the first day he arrived in Hong Kong he sent me the video and told me he thought he was a nice horse and asked me if he could ride him,” Yip said.

Excited as he was by Sunday’s result, Yip is already dreaming of what the future may hold for a horse he is already targeting at next month’s Group One QE II Cup (2,000m).

Purton delivers on Massive Sovereign in Hong Kong Derby for the ages

“He’s a very gentle and quiet horse in the stable. He would always stand in the corner and not move, but if you tell him what to do, he will do it. He’s a very special horse with a very good mind,” he said.

“My stable staff for the past week, they have all concentrated on this horse. They’ve been waking up early to give the horse treatment and taking care of him very well. I need to thank my stable team, the owner, the jockey and my assistant trainer.

“I’ve already entered him for [the QE II Cup] at the end of April. I will see how the horse pulls up. If he’s good and he improves, I will go this way.”