Stan Wawrinka knocked out fourth seed Milos Raonic and Damir Dzumhur ousted third seed Stefanos Tsitsipas on a day of surprises at the ABN AMRO World Tennis Tournament in Rotterdam.
Swiss veteran Wawrinka won in two sets against Canadian Raonic, triumphing 6-4 7-6 (4) in the second round.
Greek star Tsitsipas did not even make it that far, going down 6-4 1-6 7-5 to Bosnian Dzumhur in their first-round clash.
Wawrinka will meet another Canadian next after Denis Shapovalov beat Tomas Berdych 6-4 6-3.
Elsewhere in the first round, Daniil Medvedev beat Jeremy Chardy 7-6 (2) 6-2, Marton Fucsovics sank Martin Klizan 7-6 (4) 6-4 and Jo-Wilfried Tsonga was a 6-1 6-4 winner against Thomas Fabbiano.
Gael Monfils won his second-round meeting with Andreas Seppi 4-6 6-1 6-3.
