MONTREAL, QC - AUGUST 09: Karen Khachanov of Russia prepares to hit a return against Alexander Zverev of Germany during day 8 of the Rogers Cup at IGA Stadium on August 9, 2019 in Montreal, Quebec, Canada. Karen Khachanov of Russia defeated Alexander Zverev of Germany 6-3, 6-3. (Photo by Minas Panagiotakis/Getty Images)
