Having driven 10 hours and 1000km with his mother, brother and 88-year-old grandma Daphne from Barcelona to Paris the night before, Trungelliti etched his name in French Open folklore with his stirring 6-4 5-7 6-4 6-4 first-round triumph over Tomic on Monday.
"It was good, no? It's beautiful," the Argentine beamed after guaranteeing himself the biggest pay day of his career, a 79,000 euros (A$122,000) cheque - or more if he continues his incredible run.
The 28-year-old had returned to his Spanish base after losing his final-round qualifying match last Thursday to Hubert Hurkacz.
But when his coach noticed Egyptian lucky loser Mohamed Safwat playing Grigor Dimitrov on centre court on Sunday, he urged Trungelliti to check if he too might be required to fill a place in the main draw following a spate of late withdrawals.
"So I ask, and then somebody told me that I was the first alternate," Trungelliti said after replacing Tomic's fellow Australian Nick Kyrgios in the draw.
"We were at home with my family, actually; my brother and my grandma and my mum came a week ago. So supposedly they were going to come here, but then I lost so I left.
"Then they rent a car just to take a look in Barcelona or some other cities in Spain that is beautiful.
"So, actually, my grandma was in the shower and I told her: 'OK, we go to Paris'.
"We needed grandma for sure."
Not trusting flights and with no rail network between Barcelona and Paris, the Trungelliti clan squeezed into the small hire car instead.
"It was good," he said of the incredible journey.
"Coffee after two hours. Eat. And then I had a dinner at nine or something like that so we arrived around (midnight) at the club. Slept five hours, maximum. And then we came here 7.30 or something like that."
Despite the rush, the South American said the long drive at least allowed him time to mentally prepare for Tomic.
"Physically, I had no idea," Trungelliti said.
"So, in the end, it was good. I didn't feel pressure at all. Nothing.
"I lost on Thursday here, so Friday I didn't play, Saturday I didn't practise. Sunday, nothing. So just today the warm-up, and then we went to the court."
The world No.190's famous victory earned the South American a second-round shot at Italian Marco Cecchinato, a five-set winner over Romanian Marius.
