Washington, DC, USA, 6 August 2015 | tennis.com.au

Sam Stosur has coasted into the quarterfinals of the Citi Open in Washington DC with a straight-sets victory over Irina Falconi.

Stosur beat the American 6-1 7-5 in one hour and 20 minutes, booking a showdown in the last eight with Monica Niculescu.

The Queenslander beat Niculescu earlier this year in the opening round of the Australian Open.

Stosur’s victory on Wednesday took her head-to-head record over Falconi to a perfect 3-0.

She produced eight aces and won three quarters of her first serve points in yet another dominant serving display.

The victory also boosted her winning streak to seven; Stosur arrived in Washington on the back of a title run at the WTA claycourt event in Bad Gastein, Austria.