Tenth-seeded Karen Khachanov pointed to his pregnant wife in the stands after beating No. 8 Juan Martin del Potro 7-5, 6-3, 3-6, 6-3 to reach his first Grand Slam quarterfinal.

The Russian told his support team in an on-court interview, ''Let's go for more.''

For a spot in the semifinals, Khachanov will face Dominic Thiem, last year's runner-up.