Lleyton Hewitt has been left to fly the Aussie flag on his own at the US Open, after big Aussie hopes Sam Stosur and Bernard Tomic crashed out in the first two rounds.

Tomic seemed to be in control of his second round match against British qualifier Daniel Evans overnight, up a set and a service break after just over half an hour of play.

However Evans staged a dramatic comeback to take the next three sets, rolling Tomic 1-6, 6-3, 7-6 (7-4), 6-3 to grab the spot in the third round- something Tomic has never achieved at Flushing Meadows.

Both players struggled to hold serve in a tight second set, with the Brit eventually holding his nerve to square the match. He went on to claim the third in a decisive tie-break and a disheartened Tomic never looked like getting himself back in the match.

The 20-year-old admitted after the match he became too passive after taking an early lead. "From then he started playing better. I couldn't really hit the ball. I was afraid, just… I don't know. It was pretty bad after that, second and third set,'' he said.

"The first set I didn't give him a rhythm. I went after my shots, played aggressive, didn't give him time. After, when I slowed down the pace, which I sometimes do – don't know why – he started playing better. Gave him the opportunity to come into the match. Then after I couldn't do anything.

Meanwhile Sam Stosur is likely to see her world ranking drop even further after her disappointing first round loss to American teenager Victoria Duval. Stosur also stumbled from a set and service break up to lose 5-7 6-4 6-4 against the 17-year-old Duval, who is ranked 296 in the world.

The result highlights a dramatic fall from grace from Australia’s top ranked female player, coming at a grand slam that she won just two years ago. The 28-year-old had won 15 of her past 17 matches at the US Open since 2009, prior to one of the worst results in her career.

"First round of the US Open is not a good feeling,'' Stosur said. "I'm probably going to give a much worse answer right now than maybe a more logical or less emotional one tomorrow.

“She held it together. She kept going for it. When she got the chance to step up and hit a winner, she did it, just like on match point.”

Having recently split with her long time coach, many are predicting Stosur may need to take a break from the sport. Although Stosur had entered this year's event with confidence after winning nine of her 11 matches on American hardcourts over the US summer.

The loses from our highest seeded Men’s and Women’s players mean that veteran Lleyton Hewitt is the only remaining Aussie from a contingent of nine in the singles draw at the New York event.

Hewitt will take on sixth seed and fellow former US Open champion Juan Martin del Potro in his second round match tonight.

Despite being an overwhelming underdog in the tournament which he won all the way back in 2001, Hewitt is upbeat that we will have an Aussie in the second week of the year’s final grand slam.

"Another step up. But that's why I'm here, to have a crack at the best guys," Hewitt said. "You have the opportunity to play the best guys out here at slams and at Slams this year he is one of them.

"It's going to be a big test and I'm looking forward to it."

Damien Bellemore