Nick Kyrgios was again troubled by injury as he crashed out of the European Open to Ruben Bemelmans.
The third seed, who was given a bye in the first round in Antwerp, was playing his first singles match since being fined for his latest indiscretion in Shanghai, when he retired suddenly after losing the opening set to Steve Johnson.
Kyrgios later blamed a stomach upset but flouted ATP rules by not undergoing a medical examination and forfeited his prize money.
The Australian's problems here appeared to be related to his hip, which troubled him during the summer, and he went down 6-7 (3/7) 6-3 6-3 to Belgian Bemelmans.
Bemelmans' countryman Steve Darcis profited from Cedrik-Marcel Stebe's retirement while there were also wins for Joao Sousa and Julien Benneteau.
Nick Kyrgios of Australia attends a press conference
Image credit: Getty Images
At the Kremlin Cup in Moscow, third seed Adrian Mannarino defeated Lukas Rosol 6-3 7-6 (7/4) to reach the quarter-finals while sixth seed Damir Dzumhur battled to a 4-6 7-5 6-4 win against qualifier Yuki Bhambri.
Third seed Jack Sock reached the final of the Stockholm Open 12 months ago and ended a five-match losing streak with a 6-4 6-4 victory over Jeremy Chardy to move into the quarter-finals.
In the last eight he will face Fabio Fognini, who had to save a match point before beating young Swede Elias Ymer 6-4 3-6 7-6 (9/7).
It was a tough day for the Ymer family, with Elias' brother Mikael also losing a tight match 1-6 7-5 6-4 to fifth seed Mischa Zverev.