The icing on the cake was the senior McKee's 75th birthday on the second premier race day of the Rush Munro's Hawke's Bay Spring Racing Carnival trilogy.
While Trevor drives the horse floats these days, it's fair to say the legendary trainer of Sunline fame has mentored his 49-year-old son well.
So did Trevor teach him everything?
"Well, he's been pretty good all the way," the father said soon after coming out of the swab room of the stabling area as Mufhasa went through his tests.
"It's been first class because he has been willing to learn all the way through, unlike some children who don't want to listen to their dads because they know better.
"He's one of those who's taken everything inwards and came through all right," he said, adding Stephen always had the propensity to build on knowledge gleaned from anyone.
An assistant trainer under his father during the Sunline era, Stephen was a model understudy and the senior McKee attests to how demanding it can be to train a Group I horse.
Eight-year-old champion Mufhasa, who on Saturday finished a length ahead of Fleur De Lune and Jason Jago, is a class act but how does the Pentire gelding compare with Sunline?
"He's a very good horse but still not quite up to her grade.
"She [Sunline] was one of those freak performers and I don't think we'll see anything like her again," Trevor McKee said.
Sunline was a bold frontrunner who threw down the gauntlet to her rivals and most of the time they had no answer. She won 32 races from 48 starts from 1100m to the 2040m of the Cox Plate which she won twice. Her pet distance was 1600m over which she won eight times, claiming two Doncaster Handicaps and the Hong Kong Mile.
McKee, who retired as a trainer in August 2006, originally raced Sunline on lease before he and his partners paid A$40,000 ($49,000) for the option to own her outright.
Pundits often rank Sunline as the second best New Zealand horse after the great Phar Lap.
"Very limited" now, he felt Mufhasa would go to Australia for a couple of races and that would probably be it for the sprinter/miler.
He took his hat off to Auckland rider Spratt who overcame her demons from the Makfi Challenge on September 1 when she dropped the whip to settle for fourth place.
"Everyone can drop a whip and make that sort of mistake," said the godfather of trainers who intended to celebrate victory with his family and grandchildren at their Ardmore property.
"It's a great game this racing game. It's been very good to us over the years so, hopefully, it'll continue.
The junior McKee was delighted to have kept Mufhasa on the track for so long and to keep winning.
The No 10 barrier didn't bother him and he was happy Spratt stuck to the plan of bringing him into the inside early.
Reflecting on the rider's mishap with the whip in the Makfi Challenge, Stephen McKee said: "It wasn't the only excuse the last time but it didn't help.
"She came out to me first and said, 'I've got a rubber band on my hand to make sure I keep the whip'.
"But it's all good because these things happen to jockeys from time to time."
Mufhasa won't be competing in the 2040m $300,000 NZ Bloodstock Insurance Spring Classic on October 6.
"There are no races for him in New Zealand until early December [at the 1600m Group I Captain Cook Stakes in Trentham, Wellington, which he won last year] but having said that he may go to Melbourne in October for the Toorak Handicap, which he won last year.
"We'll try to come back next year if the horse is fit and well."
A grinning Stephen McKee lauded his father for teaching him the tricks of the trade.
"Some things I've gladly forgotten but other things I've had to learn extra but, no, he's taught me good," he said with a laugh, adding it was rewarding to win in front of his father who still made invaluable contributions to the stable.
Asked how he was going to celebrate the victory, Stephen said it depended on how tired they were going to be after the six-hour drive home on Saturday night.
Mufhasa clocked 1min 34.88sec over the 1600m on a good track.
Michael Coleman rode Xanadu to third place.
Jonathan Riddell crossed the line fourth with Guiseppina who looked agitated from the parade Ring as the handler led the mare to the bird cage.
Riddell, who took 2011 Horse of the Year Jimmy Choux to great heights, required extra assistance to mount the Steven Ramsay-trained Guiseppina.
He's Remarkable and Vinnie Colgan brought home a cheque in fifth place while Danielle Johnson and Postman's Daughter could only deliver a sixth placing.