For the third time in his four matches on the grass this week, Cerundolo was taken to a deciding set but again stayed composed to prevail 6-7 (5-7) 6-3 6-4 on Saturday and set up a final against 2024 champion Tommy Paul.
American Paul, who never got the chance to defend his title last year because of injury, beat Frenchman Ugo Humbert 6-3 6-3 in the other semi.
Cerundolo confessed this week to never having played on grass before turning professional but the 27-year-old seventh seed showed the surface holds no fear for him as he edged past Nakashima, who'd knocked out top seed de Minaur in the quarters, in two hours and 43 minutes.
The only other Argentine to reach the Queen's final was David Nalbandian in 2012 although that did not end well for Nalbandian, who was defaulted against Marin Cilic after kicking an advertising hoarding in anger and injuring a line judge.
"I stayed there competing. I was saying to the crowd, I'm leaving it all here on the court and it worked out. I'm super happy to be here, in this tournament, in the final," the world No.27 said after reaching his first ATP 500 final.
Nakashima twice recovered from having his service broken in the opening set before winning a tiebreak with some typically solid tennis. He also broke serve at 2-2 in the second set but Cerundolo managed to find another level.
He won a 30-stroke rally to break back and swept four games in succession to level the match.
Cerundolo forged ahead in the decider only to be pegged back to 4-4 but Nakashima missed a routine volley to hand over another service break and the Argentine finished the job.
With Reuters
