Evgeny Donskoy

WATCH: It's been a shocking, thrilling, downright nutty week of tennis

Roger Federer choked, Andy Murray survived and Nick Kyrgios upset Novak Djokovic.

Youzhny loses to Donskoy, then sits in his box for following match

The two Russians, who are in Dubai this week, share the same coach.

Federer blows three golden opportunities in stunning loss to Donskoy

Federer led 5-2 in the third set and 5-1 in the deciding tiebreaker.

Donskoy saves match points to beat Khachanov in Sweden

Two-time champion Ferrer and Sousa, who reached the final two years ago, are the top two seeded players this year.

Donskoy upsets Coric at Kremlin Cup; Pavlyuchenkova advances

The world No. 118 only faced one break point against the 39th-ranked Croatian.