Karen Khachanov beats Dominic Thiem 2-1 at Mubadala World Tennis Championship

Dominic Thiem of Austria in action during his match against Karen Khachanov of Russia at the 2018 Mubadala World Tennis Championship in Abu Dhabi, the United Arab Emirates (UAE), on Dec. 29, 2018. Dominic Thiem lost 1-2. (Xinhua/Mahmoud Khaled)