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…