Mikhail Kukushkin reached the quarterfinals of the St. Petersburg Open on Tuesday, while Adrian Mannarino was eliminated in the second round.

Kukushkin, the St. Petersburg champion in 2010, recovered from 4-2 down in the first set to win 7-6 (2), 6-2 against 2017 champion Damir Dzumhur, who saved four match points before he was finally beaten.

The sixth-seeded Kukushkin will play either Karen Khachanov or Joao Sousa in the quarterfinals.

The seventh-seeded Mannarino was beaten 6-3, 6-1 in just over an hour by qualifier Egor Gerasimov, who last reached a tour-level quarterfinal in October 2018.

Norway's Casper Ruud came through a tough first-round encounter with Alexander Bublik 6-7 (3), 6-4, 6-2. The eighth-seeded Ruud plays Salvatore Caruso in the second round.

It was the first indoor win on the ATP tour for the 20-year-old Ruud, who is usually considered a clay-court specialist.