Mannarino edged top-seeded Gilles Simon 2-6, 6-4, 6-4. Mannarino lost his serve four times but only once after the first set, and converted all three of his own break opportunities in the second and third sets.
Sela was on the court less than an hour in blitzing No. 3-seeded Alexandr Dolgopolov 6-2, 6-2. He lost just 14 points in eight service games. He established control with a first set in which he dropped five points in four games.
Unseeded Mikhail Kukushkin is back to defend his 2010 St. Petersburg title, which is his only ATP championship. With Simon eliminated, Janko Tipsarevic, at No 2, is the highest seed. Tipsarevic has won two of his last four tournaments, including taking the Kremlin Cup Sunday.