Top seeds Andrey Rublev and Aryna Sabalenka struggled through determined challenges to avoid upsets with three-set triumphs on Wednesday and advance at the ATP and WTA Washington Open. World number eight Rublev fired 15 aces and rallied after a rain delay in dispatching 20-year-old Frenchman Luca Van Assche 4-6, 6-3, 6-4