Ugo Humbert upsets Alexander Zverev at Halle Open; Andrey Rublev only seeded player in quarters

HALLE, Germany -- Ugo Humbert upset Alexander Zverev in the second round of the grass-court Halle Open on Thursday to leave Andrey Rublev as the only seeded player to reach the quarterfinals.

The third-seeded Zverev hit 20 aces but it wasn't enough as Humbert won a close match 7-6 (4), 3-6, 6-3.

Zverev is a two-time runner-up in Halle but has yet to win a title on grass. Humbert is in back-to-back quarterfinals on grass after doing the same in Stuttgart last week.

It's the first time in Halle's 28-year history that seven of the eight quarterfinalists are unseeded, the ATP said. Fourth-seeded Rublev is the exception after the Russian beat Jordan Thompson on Wednesday.

U.S. player Sebastian Korda, son of former Australian Open champion Petr Korda, beat Kei Nishikori 2-6, 6-3, 7-5 to set up a quarterfinal against Humbert. Korda won his first tour title in Parma on clay last month and is in his first tour-level grass tournament.

Nikoloz Basilashvili won against Arthur Rinderknech 6-2, 7-5 after saving two set points at 5-4 down in the second set. He will play South African Lloyd Harris, who beat qualifier Lukas Lacko 6-3, 7-6 (8).