The moment happened away from all of the fans and cameras at Allianz Stadium a few minutes after the Sky Blues had completed an exhausting clash with Melbourne Victory by finally taking the title in a penalty shootout on Sunday night.
It was Vukovic's save of the spot-kick by Victory winger Marco Rojas - the only actual save by either goalkeeper among the three unsuccessful penalties in the shootout - that set Sydney up for the winner-take-all attempt that was duly converted by Milos Ninkovic.
Vukovic spotted Kristy coming down the tunnel with their toddler son Harley and raced over to meet her.
Asked what his wife said to him, Vukovic replied: "She just said 'you finally did it'. She knows how much a grand final win meant to me and she has been there through all the downs in my career and there have been so many downs.
"She knows how desperate I was to lift that trophy. She's been such a pillar of strength for me not just this season, not just this last 12 months, but throughout my whole career and the whole time we've been together.
"I cried, mate, in the tunnel when she said that, because it just summed it all up for me. Kristy handed Harley over to me and that's what I'd dreamt of, winning the championship and having our son there with me and that's what happened, so I couldn't be happier."
The grand final victory topped off what has been an emotional few months for Vukovic and his wife.
Their son Harley, who suffers from biliary atresia, a condition which blocks bile ducts and causes liver damage, underwent a successful liver transplant in February.
Vukovic, 32, is an A-League institution. He has played for half of the clubs in the competition - Central Coast Mariners, Wellington Phoenix, Perth Glory, Victory and Sydney - and holds the record for most games, with 278.
He had won a Premier's Plate with Central Coast and, of course, Sydney this season, and an FFA Cup final with Victory, but he had lost three A-League grand finals (two with the Mariners and one with Perth) and two FFA Cup finals (one each with Perth and Sydney).
Plus, he had tried his luck playing with overseas clubs twice only for both moves to come unstuck because of circumstances out of his control, and a ban for slapping the hand of a referee prevented him from representing Australia with the Olyroos at the 2008 Beijing Olympic Games.
A grand final win was what he craved more than anything.
"The three grand final losses, a couple of FFA Cups, a failed move to Turkey, failed move to Japan, missing out on the Olympics, there have been a few things," Vukovic said.
"I think I was overdue a grand final win and I don't know how I would've taken a fourth loss. I'm just so happy it worked out the way it did."
The championship success on top the dramatic improvement in Harley's previously ill health has left Vukovic counting his blessings as he prepares for a well-deserved off-season rest.
"At the start of every season you make plans, you know, and very rarely do they come to fruition, but this year everything Kristy and I planned as a family and everything we all planned as a club has come to fruition," he said.
"It's been an amazing year and I don't know how I'll ever top this season."