Jan Tratnik of Team Visma-Lease a Bike looked set to take the stage after launching a solo break from the leading group with more than 30 kilometres left to race, but was overtaken by Paret-Peintre with less than 3km to ride.
"I was there to get a good result in the stage and why not win? Now I have a stage win for my first professional win," Decathlon-AG2R La Mondiale's Paret-Peintre said.
The 142-km ride from Pompei to Cusano Mutri ended with an 18km finishing climb of Bocca della Selva, and Tratnik had to settle for third place in the end.
"The last four kilometres was the hardest and I said, okay if I want to attack it's in the last four km, so I was waiting, waiting, waiting on the last climb and when I saw the last 3km, I attacked," Paret-Peintre said.
Romain Bardet (Team DSM-Firmenich) made it a French one-two, as he also went past Tratnik to come in 29 seconds behind the winner.
Stage 10 came after Monday's rest day and, while race leader Tadej Pogacar of UAE Team Emirates was happy to take it easy in the peloton, others grabbed their chance for glory, with a large group getting away from the main bunch.
Tratnik's solo attack looked like it would pay off but he was hunted down by Paret-Peintre and Bardet and his brave effort was foiled as tiredness set in.
"I think three, four kilometres to go, I started to feel a bit of weakness in my legs," Tratnik said. "I look behind and they passed me with double speed and then for me it was just a battle to the finish line."
On stage eight, Paret-Peintre was caught four km from the end by the peloton but this time he claimed the win, following in the footsteps of his older brother who won a stage in last year's Giro.
"Doing it one year after my brother is special," the 23-year-old said. "Last year when he won his stage, my name was written by mistake on the bottle of champagne. This time, I'm really the winner."
Slovenian Pogacar still holds a lead of two minutes 40 seconds over Colombian Daniel Felipe Martinez of Bora-Hansgrohe, with Ineos Grenadiers' Welshman Geraint Thomas in third, 18 seconds further back.
