Samantha Stosur has advanced to the US Open quarter-finals with a dramatic and courageous three-set victory over Elena Dementieva on Monday.

Stosur had some nervous moments and survived four match points to beat the Russian 12th seed 6-3 2-6 7-6 (7-2) and set up a last-eight showdown on (Wednesday AEST) with defending champion Kim Clijsters.

Stosur looked to be on her way out of the tournament when she was down a break in the deciding set.

Dementieva struck a forehand wide on her first match point trying to serve it out at 5-3.

The French Open runner-up then bravely staved off another three match points in the next game to level at 5-5.

After squandering those opportunities, Dementieva then crumbled to drop her serve in the following game to hand Stosur the chance to finish the job.

But the Aussie missed her chance, Dementieva forcing the Queenslander into a backhand error on her first match point, before breaking to force the tiebreaker.

Finally, though, it was Stosur - who also saved a match point against world No.1 Serena Williams in this year's French Open quarter-finals - who prevailed when Dementieva fired a forehand long after two hours and 38 minutes.

Stosur will now meet Clijsters, who has won 18 successive matches at Flushing Meadows, and had little trouble in disposing of former world No.1 Ana Ivanovic 6-2 6-1.

The Serbian, who won the French Open in 2008, is on the comeback trail after injuries and poor form saw her ranking plunge more than 60 places.

Her fourth-round clash with Clijsters was her biggest test in recent times and the 6-2 6-1 result proved Ivanovic still has a long way to go.