Defending champion Iga Swiatek held off a fierce challenge from Ukraine"s Marta Kostyuk to reach the French Open quarter-finals with a 6-3 6-4 victory on Monday. The eighth-seeded Pole has now won 22 consecutive sets at Roland Garros going into her clash with Greek 17th seed Maria Sakkari as she bids to become the first woman to retain theRoland Garros title since Justine Henin in 2007. Against an 18-year-old opponent who threw everything at her, Swiatek kept her composure on an empty court Philippe Chatrier, with fans not allowed to attend due to Paris"s 9pm COVID-19 curfew. "There were so many differences (from a day match)," said Swiatek. "It was hard for me to adapt. The light are really bright and I had to adjust, sometimes I was facing the lights when I had to smash, it was hard." Kostyuk, who had not dropped a set in powering through the first three rounds, piled on the pressure early on to put Swiatek on the back foot and earn a break for 2-1. An unfazed Swiatek, however, broke straight back before gaining the upper hand in the eighth game when Kostyuk"s attempted backhand down the line went wide. The Pole served out to take the lead after a hugely competitive set in which she faced five break points. Swiatek capitalised on her opponent"s errors to break for a 2-1 lead in the second, only for Kostyuk to level at 2-2. The decisive break for Swiatek came in the seventh game when Kostyuk netted a sliced forehand while attempting to retrieve a lob. Kostyuk bounced her racket in frustration after Swiatek earned a match point at 5-3, but the Pole squandered that chance. Kostyuk went 30-0 up in the 10th game but Swiatek won four points in a row, wrapping it up with a superb lob at the end of a quick exchange at the net. "Her defence was crazy, it was hard for me to finish the points a few times," said Swiatek. "She was getting everywhere, so big bravo to her, she has a bright future ahead of her."