Third seed Belinda Bencic has been knocked out of the Citi Open in Washington, losing 6-2, 6-4 to Anastasia Pavlyuchenkova in the second round.
It was the serve of Pavlyuchenkova, who is ranked 40th in the world, that was the cornerstone of her victory, as the Russian won 84 percent of points on her first serve. Pavlyuchenkova broke Bencic in the third game courtesy of a scorching backhandand, and saved both the break points she faced in the first set.
The 24-year-old Russian continued to take the attack to Bencic in the second set, in what as a tighter affair than the first. However, it was Pavlyuchenkova who took her chances, breaking Bencic on what was the lone break point of the set, to secure the victory in one hour and 12 minutes.
Pavlyuchenkova will face Christina McHale in the quarter-finals after the American defeated Yulia Putintseva 6-2, 1-6, 7-5 in a gruelling match that lasted two hours and 45 minutes.
Sloane Stephens also booked her spot in the last eight after fourth seed Svetlana Kuznetsova pulled out of the tournament with a lower left leg injury on Wednesday.
Joining Stephens in the quarter-finals is top seed Ekaterina Makarova, who triumphed over British qualifier Naomi Broady 6-4, 7-6 (2).