Harry Redknapp saw his side thrashed 5-1 when he came up against Ange Postecoglou in their only managerial meeting seven years ago.
And that was enough to persuade the veteran boss that the Celtic boss is the perfect fit for Spurs.
Postecoglou has been heavily linked with a move to take over Tottenham Hotspur, who are on the hunt for yet another manager after a poor season.
Redknapp, 76, went head-to-head with Postecoglou when he was manager of Jordan for a short spell in 2016. After thrashing Bangladesh 8-0 in a World Cup qualifier, he came up against Postecoglou's Socceroos and Australia crushed them 5-1, which included goals from future Celtic star Aaron Mooy and Tom Rogic.
And a chat with Tim Cahill, who scored a double, persuaded the former Spurs and West Ham boss about the merits of the future Hoops boss.
He said: "Back then Tim Cahill told me what a fantastic coach he is and that was good enough for me.
“I knew he had to be good if Tim was bigging him up that much and I’m not really surprised at what he’s achieved. I’m sure there’s a lot more to come yet.
"I was impressed when I met Ange, and he’s been wonderful for Celtic - even though some people didn’t know much about him and thought he might struggle there.
"No disrespect to Celtic, but when a Premier League club like Tottenham shows interest then you have to take notice.
"They have a football stadium as good as anywhere in the world and an amazing training ground - now they need to get things right on the pitch.
“They clearly need to bring in some new players in different areas and Ange has already shown at Celtic how clever he is with his recruitment, especially bringing in the quality boys from Japan, which is obviously a market he knows very well.
“If the club can keep him, Tottenham still have the best centre forward around, for me, in Harry Kane - so it’s a great opportunity there for Ange."
And Redknapp, in an interview in Australia, insisted he always suspected Postecoglou would be in the frame for the job when Spurs axed Antonio Conte.
He said: "The moment Spurs sacked Conte back in March, Ange Postecoglou’s name was the first one that jumped into my mind.
"I mentioned it to plenty of other people also because I genuinely feel he’d be a perfect fit for Tottenham.
"I thought he’d be a front-runner then for sure but nothing seemed to happen until the club was initially linked with ex-Bayern Munich boss Julian Nagelsmann.
"But now I see Ange is very much in the frame and that’s a shame for Celtic fans because he’s done an incredible job there.
"This is the Premier League we’re talking about here. You saw that with Steven Gerrard who did a great job at Rangers and then got his chance at Aston Villa.
"I think if Spurs make an approach it will be a difficult one for Ange to turn down. He’s been excellent - you only have to see the way his teams play.
"It’s great on the eye and I feel he’d be a great choice for Tottenham. I think Spurs need to be less timid and have a go at teams, when I was there we played with two wingers home and away in Aaron Lennon and Gareth Bale and played on the front foot.
"That’s the way I like to see teams play and I think that's what the supporters want. Ange would bring that sort of approach."
