Washington, DC, USA, 22 July 2016 | AAP

Sam Stosur is in a perfect position to claim her first tournament victory of 2016 as the seeds continued to tumble at the Citi Open in Washington.

The Australian’s draw opened up significantly when Lauren Davis knocked out third-seeded Puerto Rican Monica Puig 6-4 6-2 on Thursday.

The result leaves Stosur heading a top half of the draw where 77th-ranked Italian Camila Giorgi is the next highest-ranked player.

Giorgi advanced to the quarters thanks to a walkover from Austrian Tamira Paszek.

Stosur next faces 22-year-old American wildcard Jessica Pegula in the quarters – a match scheduled for Saturday morning AEST – and would have to like her chances of winning her first title since July last year when she won in Bad Gastein, Austria.

The Australian advanced to the quarterfinals when Caroline Wozniacki retired hurt due to an elbow injury in their second-round match on Wednesday.

In the bottom half of the draw, fourth-seeded Frenchwoman Kristina Mladenovic beat 2013 Wimbledon runner-up Sabine Lisicki 6-3 6-3 and Japan’s Risa Ozaki edged out Briton Naomi Broady 6-1 5-7 6-4.