The Argentine will attempt to win the title for the second consecutive year after scoring a 7-6(2), 6-4 victory over third seed Stanislas Wawrinka oon Saturday.
Potro is now 26-2 for the season, having won one title and reached another on the tour.
Gasquet scored a 2-6, 7-6(1), 7-5 victory over fourth-seeded Spaniard Albert Ramos over three hours.
del Potro leads their head to head 3-1 on tour.
Meanwhile, at the ATP Serbia pen, run by Novak Djoovics family, Benoit Paire will take on Andreas Seppi on Sunday for the title.
Piare upset top seed Pablo Andujar 6-3, 1-6, 6-3. “It was a tough match. Andujar is a really good player,” commented Paire. “For me, the first set was very good. After, I was a bit tired. But in my head, I was thinking at one-set all, I could win if I played my best. It’s my first ATP [World Tour] final. For me, it’s unbelievable.”
Seppi reached the final with a 2-6, 6-2, 7-5 win over fourth-seeded David Nalbandian.