German wild card Alexander Zverev reached the quarter-finals of the ABN AMRO World Tennis Tournament in Rotterdam, causing a huge upset by getting past third-seeded Gilles Simon on Thursday night.
In a late night match, the 18-year-old defeated world number 15, Simon, 7-5, 3-6, 7-6 (7/4) after almost three hours on court.
The 70th ranked Zverev hung in until the tie-break and some costly errors by the Frenchman gave his young opponent the victory.
After defeating Canada’s Vasek Pospisil in the opening round, Zverev has set up a quarter-final clash against fifth seed Gael Monfils on Friday.
In other action on Thursday, Span’s Roberto Bautista Agut got past Jiri Vesely 4-6, 6-2, 6-4 and will next be up against Slovakian Martin Klizan after he dispensed with Marcos Baghdatis 6-3, 6-2.
Veteran French qualifier Nicolas Mahut beat countryman Jeremy Chardy 7-5, 6-2 and will next be up against Viktor Troicki, who beat Hyeon Chung 7-6, (7/5), 6-2.
Second seed Marin Cilic will also be in action on Friday against Philipp Kohlschreiber of Germany for a semi-final berth.