Stefanos Tsitsipas and Dominic Thiem both won twice on the third weekend of the Ultimate Tennis Showdown, behind closed doors in France.
Novak Djokovic was among the players to contract coronavirus after the Adria Tour, with Dominic Thiem's manager blaming the Serbian.
Filip Krajinovic progressed at the expense of Novak Djokovic, but was unable to topple Dominic Thiem in the final.
Dominic Thiem mengatasi Filip Krajinovic dalam pertarungan tiga set untuk menawan kejohanan pertunjukan, Jelajah Adria, di Belgrade awal pagi tadi.
The Belgrade crowd will not get to see Novak Djokovic in the final of the Adria Tour exhibition event at the Novak Tennis Centre.
As the Adria Tour got underway, Novak Djokovic was beaten for the first time this year.
Dominic Thiem dan Alexander Zverev mengundang keraguan sama ada Terbuka Amerika Syarikat (AS) akan diteruskan seperti yang dijadualkan selepas diselubungi wabak COVID-19.
Another two top-10 players cannot see how the US Open can take place unless there is a significant change of circumstances.
The Adria Tour, which will feature Novak Djokovic and Dominic Thiem, is to take place in Balkan cities, beginning next month.
As Novak Djokovic celebrates his 33rd birthday, we reflect on his most epic matches on the grand slam stage.