Russian 17-year-old Andreeva, the youngest grand slam semi-finalist since Martina Hingis in 1997, froze on the big stage as Paolini, 28, reached her first major final.
It was a match with the biggest age gap between two women in a Roland Garros semi-final since Chris Evert, at 30, defeated 15-year-old Gabriela Sabatini in 1985.
Paolini is also inexperienced at this level, though, having until this year never progressed past the second round at a grand slam.
But she held her nerve where Andreeva’s deserted her, the youngster squandering all six of the break points she created.
A 6-3 6-1 victory in an hour and 13 minutes saw Paolini become only the third Italian woman to reach the Paris final in the Open era, and will see her break into the top 10 for the first time in her career.
World number one Iga Swiatek awaits in the final, and the Pole may not lose too much sleep after watching this match.
Nevertheless, Paolini was determined to enjoy her moment in the Paris sunshine.
