The Australian No.1 admitted he'd been stressing about sealing his place among the season's best eight players, who'll all feature in the November championship next month.
So, having tried not to let his chase for the prize distract him, de Minaur was delighted to discover after beating Karen Khachanov 6-2 6-2 to move into the Paris Masters quarter-finals on Thursday that he had now done enough to guarantee his spot.
"That's actually confirmed? It is? Geez, that feels amazing. I mean, there's a lot of stress going on the last couple of weeks. You just made my day a whole lot better," beamed de Minaur at La Defense Arena, after learning the news from a courtside interviewer.
"I did my best not to keep an eye out on on the race, but it was too hard. You don't want to add extra elements to your head.
"I mean, there's a feeling in the back of your mind, you kind of know where everyone's at, but I didn't know that with the win today, I was actually qualified. So, I'm extremely stoked."
De Minaur reached the Finals for the first time last year after an injury-disrupted season, but lost his three round-robin matches.
But he reckons it will be different when he battles a Turin field which, as it stands, will feature Carlos Alcaraz, Jannik Sinner, Alexander Zverev, Novak Djokovic, Ben Shelton and Taylor Fritz, with one other place to be contested between eighth-placed Lorenzo Musetti and Felix Auger-Aliassime.
"100 per cent it's a different feeling," de Minaur said.
"I'm feeling physically great, which is already a much better version of myself than last year, and I'm extremely stoked with my level.
"I'm looking forward not just to make up the numbers this time and hopefully be able to do some damage over there."
If he can replicate the sort of efficiency he showed against 10th seed Khachanov, who held a 2-1 head-to-head against the Aussie going into the match, 'Demon' will definitely have a chance.
De Minaur, at his joint-highest ATP ranking of No.6, broke the Russian's serve four times and offered up only three break points himself, all of which he saved, going on to wrap up one of his better wins of the year in just 68 minutes.
A 55th victory of his best season has also put him in the Paris quarter-finals for the third successive year, where he'll meet Alexander Bublik, who handed him his most shattering defeat of the year, also in Paris, at the French Open in May.
Bublik beat Fritz 7-6 (7-5) 6-2, but couldn't stop the American sealing his Turin qualification, while Shelton has also made it to the big show after beating Andrey Rublev 7-6 (8-6) 6-3.
Shelton, though, will next meet a rampant Sinner, who outplayed Francisco Cerundolo 7-5 6-1 for an amazing 23rd straight indoor hard-court victory.
The fairytale rise of Valentin Vacherot continues, with the Monaco player, whose triumph at the Shanghai Masters stunned tennis, this time reaching another ATP 1000 quarter-final by beating Alcaraz's conqueror Cameron Norrie 7-6 (7-4) 6-4.
Zverev will face 11th seed Daniil Medvedev in the last eight after the world No.3 scored a 6-2 6-4 victory over Alejandro Davidovich Fokina, the 15th seed.
Russian Medvedev enjoyed a 3-6 7-6 (7-5) 6-4 win over Lorenzo Sonego.
