De Minaur eases past inconsistent Humbert into Rotterdam final
Neither player were at their best in a semi-final marred by dozens of unforced errors but De Minaur produced more consistent tennis at the big moments, saving 10 break points.
"I tried my best to be as solid as I could and today was another great mental performance," said De Minaur.
"I was in a lot of tough moments on my serve and the fact that I was able to hang tough and find a way out of these service games was critical...
"Hopefully tomorrow I don't have to save that many break points."
The top-seeded De Minaur seized the initiative early in the first set, breaking serve in the third game as Humbert pushed a simple groundstroke wide.
Humbert had his chances to get back into the set, squandering four break points in the fourth game and two more in the eighth.
But the consistent Australian held firm, taking the set with an Humbert forehand dropping long.
More unforced errors dogged Humbert at the start of the second set, De Minaur breaking his serve in the first game as he dumped a simple forehand into the net.
The Frenchman had yet another three chances to break back into the match in the eighth game but was denied by some trademark De Minaur defending.
De Minaur sealed the win as Humbert dragged a backhand wide, leaving the Frenchman to rue 41 unforced errors and zero break points converted out of 10 chances.
The 26-year-old Australian is the first person in the tournament's history to reach three consecutive finals.
The world number eight is hoping to make it third time lucky in Rotterdam after losing the last two finals to Jannik Sinner and Carlos Alcaraz respectively.
The world's top two are not in Rotterdam this year. Sinner did not enter while Alcaraz withdrew after his epic efforts to win the Australian Open earlier this month.
Barring his way in the final will be the winner of Saturday's later clash between second-seeded Canadian Felix Auger-Aliassime and Alexander Bublik from Kazakhstan.
Auger-Aliassime despatched local hero Tallon Griekspoor in the quarter-finals, whereas Bublik ground out a three-set win over Spain's Jaume Munar.
Rotterdam has been a happy hunting ground for world number six Auger-Aliassime. He took home the trophy in 2022, beating Stefanos Tsitsipas in the final.