Saina was chasing for much of the match but she had game point at 20-19 in the first game. Young however took three consecutive points to win the first game 22-20
The world number one had lost all three of her previous major finals, including two at Roland Garros.
Ostapenko, 20, is the first unseeded player to lift the Roland Garros title in the Open era
Thiem came out with a commanding display of tennis and completely dominated the game
Paes and his American partner defeated Radu Albot of Moldova and Hyeon Chung of South Korea
Third seeded pair of Croatia's Ivan Dodig and Brazil's Marcelo Melo defeated the Indo-Romanian sixth seeded pair