Toronto: World No. 1 Novak Djokovic of Serbia headlined the top seeded players who advanced to the quarter-finals on the fourth day of the Rogers Cup tennis tournament at the Aviva Centre here. Djokovic defeated 37-year-old Czech opponent Radek Stepanek in straight sets (6-2, 6-4) on Thursday to reach the last eight stage of the tournament in nine of the last 10 times since making his tournament debut in 2007, reports Xinhua. The only year when he did not advance to the round of the final eight was 2014 when he was knocked out by eventual winner, Jo-Wilfried Tsonga in the third round. The remaining top five seeds all advanced. Second seed Stan Wawrinka (7-6, 6-2), No. 3 Kei Nishikori (6-3, 6-4) and No. 4 Milos Raonic (6-2, 6-3) all won in straight sets while No. 5 Tomas Berdych of the Czech Republic needed three sets to get by Ryan Harrison, his opponent from America. The lone upset of the night occurred when South African Kevin Anderson ousted No. 12 seed Bernard Tomic of Australia in three sets 6-4, 3-6, 6-4. Of the eight remaining players in the tournament, six of them are the top-10 seeds, with No. 10 Gael Monfils of France being the only seeded player to not receive a first-round bye. Anderson and Bulgarian Grigor Dimitrov are the remaining unseeded players. Should the top seeds come out of the top in the quarters, the tournament will be set for interesting matchups on Saturday as Djokovic would face Raonic and Wawrinka would face Nishikori. Wawrinka, Nishikori and Raonic are looking to capture their first Rogers Cup title. Raonic, a native of nearby Thornhill, Ontario, finished runner-up in 2013 and is looking to become the first Canadian in the modern era to claim the title.