Superior court coverage and retrieving from the Spanish world number three overcame stubborn resistance from the Pole for a 6-4, 6-7(5), 6-3 win to set up a clash with Australia's Alex de Minaur in Sunday's final.
"It was a very tight first set. I think he had chances to make it 6-0 so I just tried to fight every ball, every point," said Alcaraz.
"I just tried to stay in there, keep fighting all the time and it paid off," he added.
Alcaraz got off to a slow start, broken to love in his very first service game and allowing Hurkacz to race into a 3-0 lead in the first set.
He faced another break point in his next service game but saved it with a glorious crosscourt forehand and managed to hold onto serve.
Alcaraz survived another three break points and then fought his way back into the match with a break of his own, seizing the game with a forehand smash after a lengthy rally.
The momentum shifted in the Spaniard's favour and a double-fault from Hurkacz allowed the top seed to serve out the set.
Again Hurkacz had the opportunity to break, but Alcaraz held firm and sealed the set with a forehand drive volley winner.
After the topsy-turvy first set, the second proceeded more conventionally, on serve until the tie-break.
The tie-break was also nip and tuck, both players squandering chances to seize the advantage.
But a double fault from Alcaraz at 5-4 up gave Hurkacz an opportunity, and the Pole needed no second invitation, taking the set as the Spaniard netted a simple backhand groundstroke.
The decisive set started the same way as the first, with an early break of serve -- this time to Alcaraz who brought the crowd to its feet.
That eventually proved enough to break the Polish resistance, as Hurkacz failed to make inroads into the Alcaraz serve.
Serving for the set at 5-3, Alcaraz booked his place in his 22nd ATP tour final with a trademark forehand winner up the line.
"I want to be the first Spanish player to be able to win this tournament. I'm going to go for it. I'm really happy to be able to play a final in Rotterdam," said the 21-year-old.
'Happy with level'
In Saturday's first semi-final, De Minaur brought to an end the extraordinary giant-killing run of Italian qualifier Mattia Bellucci with a straight-sets win.
De Minaur was too consistent for the error-prone Bellucci, who was unable to repeat his earlier heroics against Daniil Medvedev and Stefanos Tsitsipas, going down 6-1, 6-2.
"I'm very happy with the level today," said De Minaur.
"He's been playing with a lot of confidence this whole week, so I knew it was going to be a very tough battle," added the third-seeded Australian.
Bellucci was playing his first ATP 500 semi-final but showed few nerves at the start, delighting the crowd with a trick shot winner through his legs in the very first game.
But a missed smash, an unforced error, and a double-fault gifted De Minaur an early break, and the Australian raced into a 3-0 first-set lead.
A second break followed, as De Minaur's trademark retrieving wore down the Italian. The Australian clinched the set 6-1 with a powerful forehand winner.
De Minaur also broke early in the second set, as Bellucci drifted yet another forehand wide.
Bellucci managed to hold serve at 5-2 but De Minaur wasted little time wrapping up the match, the Italian sending a backhand groundstroke long, his 30th unforced error.
Runner-up last year to world number one Jannik Sinner, De Minaur has enjoyed comfortable passage to the final, winning all his matches in straight sets.
"The Dutch crowd always treats me very well, and I love coming back here. So hopefully I can get a title this time," he said.