The Barcelona winger decided a tense quarter-final in the New Zealand capital on Friday when she scored the extra-time winner in La Roja's 2-1 win over 2019 runners-up the Netherlands.
The former sprinter showcased her speed for the goal, racing up the pitch before sidestepping a defender and firing a left-footed shot that ricocheted off the post and in.
"(Coach Jorge Vilda) told me to be sure that I was open for the passes, that I could be in the right spaces and to compete, compete as much as I could," said Paralluelo.
"I had that opportunity and I was lucky to score so I'm very happy."
Ballon d'Or winner Putellas, who has yet to have a major impact on the tournament as she returns to fitness after an ACL injury, burst into tears after the final whistle.
Paralluelo, who was born in Zaragoza to a Spanish father and Equatorial Guinean mother, made a memorable debut with the senior Spain team only last November, scoring a hat-trick in a 7-0 win over Argentina in a friendly.
She had been one of Spain's top sprinters, competing at the European indoor championships in the 400 metres in 2019, before giving up athletics to focus solely on soccer.
"The goal from Salma, it was sheer joy," said coach Jorge Vilda. "Salma is a player with enormous potential and she's not reached her best yet.
"She's a very young player who has been training one year in football specifically, and the best of Salma we'll see it in the future. Now she's excellent, but in the future it's going to be much, much more."
Sixth-ranked La Roja face either Japan, who they lost 4-0 to in the group stage, or Sweden on Tuesday for a place in the final.
Spain's historic victory on Friday came despite a tumultuous few months in the run up to the tournament.
Fifteen players, including Putellas, wrote to the Spanish federation back in September saying they were withdrawing from the national team due to events that impacted their mental and physical health.
The accusations were levelled at Vilda, who received backing from the federation. Only six of the players returned for the World Cup.
"The federation and the president have always supported us, from the very first go," said Vilda.
"Right now, I'm very happy because we think of all the management that we've had to do, and obviously (the World Cup) is not over yet."
