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

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