Washington, DC, USA, 6 August 2015 | AAP/AFP

Sam Stosur has talked up her chances of stopping Serena Williams’ Grand Slam bid if she gets the chance at the US Open.

Displaying renewed confidence, Australian second seed Stosur beat American Irina Falconi 6-1 7-5 to move into the Washington Open quarterfinals, where she’ll face Romania’s Monica Niculescu.

> READ MORE: Stosur wins again in Washington

Then she spoke about the US Open, starting late this month, where Williams is eyeing a rare calendar-year Grand Slam after her successes at the Australian Open, French Open and Wimbledon this year.

Stosur was the last woman to beat the world No.1 at the US Open, claiming her only major title in 2011 by defeating Williams 6-2 6-3 in the final.

Since then, Williams has been the queen of Arthur Ashe Stadium, winning three US Open titles in a row in a run which has reaped eight of the past 13 slam singles trophies.

“I’ve always actually quite enjoyed playing Serena. I’ve got a game that disrupts her,” said Stosur, who won a clay title in Austria last week.

“You have to have the game. My game matches up well against Serena. I’ve got the kind of weapons that can bother her.

“No doubt she is going to be feeling the pressure, as much as you can when you’ve won four slams in a row and going for a fifth.

“You know she wants to get that calendar slam. She’s not immune to the nerves and pressure.”

Despite Williams leading their career rivalry 8-3 (not counting two Stosur wins by walkover) and having won their past four meetings without dropping a set, Stosur takes confidence from a 2-1 record in their Grand Slam meetings.

Stosur lost to Williams in the fourth round at Australian Open 2010 but saved match point to win 6-2 6-7(2) 8-6 in the 2010 French Open quarterfinals.

In addition to joining American Maureen Connolly, Australia’s Margaret Court and Germany’s Steffi Graf as the only women to complete the calendar-year singles Grand Slam, Williams can match Graf’s Open era record of 22 career major singles titles by winning the US Open.

That would put her two shy of Court’s all-time record 24 slam singles crowns.

“It’s incredible what Serena is trying to achieve and what she has achieved. She is the best player of this generation by far,” Stosur said.