For while Australia's No.1 kicked off his Madrid Open quest with a clinical 6-2 6-3 victory over Italian Lorenzo Sonego on Saturday, all the talk at the Caja Magica surrounded another dismal first-round defeat for Djokovic, whose quest for 100 titles took another savage hit.
Australia's No.1 de Minaur made just nine unforced errors in a clinical, almost Djokovic-like dismantling of Sonego, before the mighty Serb, almost unthinkably, then went out and lost his third match in a row, succumbing tamely to incredulous Italian Matteo Arnaldi 6-3 6-4.
It was such a disappointing defeat for the 37-year-old Djokovic that he even pondered afterwards whether he would be back next year, a sure sign he's concerned his powers really are on the decline.
De Minaur's clay-court prowess, though, is clearly only on the up. "Como en casa" he scrawled on the camera lens after his 75-minute lesson to Sonego. In other words, the clay courts feel just like home to the Spanish-based Aussie at the moment.
The world No.7 reached the semi-final in Monte Carlo and the quarters in Barcelona, and admits he now feels completely different on the clay this year, full of confidence on a surface that once tormented him.
The 26-year-old is now looking at the prospect of a big run in the Masters 1000 event at altitude on the faster Madrid courts to set him on his way to Roland Garros.
"I was very happy with how I settled mentally, and was able to bounce back straight back after losing my serve first game and I really ended up playing some great tennis. So very happy with that."
"The thing that's been helping me out the most has been the serve. Today was a great serving day for me, and it made my life a lot easier," added the Aussie, who next faces Denis Shapovalov in the third round after the Canadian southpaw outplayed Kei Nishikori 6-1 6-4.
Asked about his striking general clay-court improvement, de Minaur added: "You see less unforced errors from me, and at the same time, you see me being a little bit more aggressive, able to hurt my opponents in different ways."
For Djokovic, though, the old assuredness has - for now at least - deserted him after he followed up his Miami Open final defeat and Monte Carlo Masters first-round loss with another sub-par outing, littered with 32 unforced errors.
"I've had a few of these this year where I lose in the first round, unfortunately," sighed Djokovic.
"Still my level of tennis is not where I would like it to be."
Asked if he'd just played his last match in Madrid, Djokovic said: "It could be, it could be. I'm not sure if I will come back. So, I don't know, I don't know what to say.
"I mean, I'll come back, maybe not as a player. I hope it's not, but it could be."
For world No.44 Arnaldi, though, beating his idol was a dream result. His message on the camera lens read simply: "OMG" - 'Oh, my god'.
Elsewhere, Stefanos Tsitsipas fought back against Jan-Lennard Struff 3-6 6-4 6-3 and will face 10th-seeded Loranzo Musetti, who beat Tomas Martin Etcheverry 7-6 (7-3) 6-2.