World number 70 Alexander Zverev shocked third seed Gilles Simon in the last 16 at the Rotterdam Open on Thursday.
Highly-rated 18-year-old Zverev posted a 7-5 3-6 7-6 (7-4) win over Simon to move into the quarter finals.
Zverev - the youngest player in the draw - was a point away from falling two breaks down but the German dug in to see off Simon, who earned plenty of admirers for his performance against Novak Djokovic in the fourth round of the Australian Open last month.
"The crowd helped me so much," Zverev said. "I really had to give it all I've got.
"When I was cramping, my box was worried, but I fought hard and stayed in there. Gilles can run all day long so it was tough for me physically."
Zverev will now take on another Frenchman in the form of fifth seed Gael Monfils.
Roberto Bautista Agut, a victor in Sofia last weekend, continued his impressive start to the year by recovering to beat Jiri Vesely 4-6 6-2 6-4.
The Spanish sixth seed already has two ATP titles to his name in 2016 and his win-loss record now reads 14-2.
Next up for Bautista Agut is Martin Klizan in the last eight following the Slovakian's 6-3 6-2 victory against Marcos Baghdatis.
Serbian eighth seed Viktor Troicki - runner-up to Bautista Agut in Sofia - defeated teenager Hyeon Chung 7-6 (7-5) 6-2.
Awaiting Troicki in the next round is Nicolas Mahut, who prevailed 7-5 6-2 against French compatriot Jeremy Chardy.