(Reuters) - Stan Wawrinka was made to work hard at the European Open on Wednesday as the Swiss veteran outlasted Feliciano Lopez 6-7(4) 6-4 7-6(4) to reach the quarter-finals in Antwerp.
The 34-year-old Wawrinka, seeking his first ATP trophy since he lifted the title in Geneva two years ago, served 17 aces -- one less than Lopez -- and converted one out of four break-point opportunities to edge the tight match.
Up next for the world number 18 is unseeded Gilles Simon, who powered past his French compatriot Jo-Wilfried Tsonga 6-4 7-5.
Wawrinka has beaten Simon four times in seven meetings but the Frenchman prevailed in straight sets the last time they played each other on the hardcourts of Shanghai in 2016.
Argentina's Guido Pella joined the duo in the last eight after beating South Korea's Kwon Soon-woo 7-5 7-5 to set up a clash with Ugo Humbert or second seed David Goffin.
In first-round action, Pablo Cuevas beat Hugo Dellien 6-4 6-3 and will take on Briton Andy Murray next. American Frances Tiafoe overcame Germany's Yannick Maden 7-6(7) 6-3.
(Reporting by Shrivathsa Sridhar in Bengaluru. Editing by Ed Osmond)