New York, Aug 31 (IANS): A battle of two former US Open champions saw a victory of the older one, who had been away from public sight for a while.

The 32-year-old Lleyton Hewitt needed four hours and three minutes to eliminate sixth-seeded Argentinean Juan Martin Del Potro in a second round match, earning himself a spot in the last 32 here at the Flushing Meadows Friday, reports Xinhua.

"It's an amazing feeling...a year and a half ago I got told I probably wouldn't play again with the surgery I had. I love being out in that atmosphere, sucking up every second of it," said Hewitt.

Hewitt has great memories in the Arthur Ashe Stadium, winning the first of his two Grand Slam titles 12 years ago, and many spectators also had in mind that the current World No.66 used to stay be the No.1 many years ago.

Hewitt had played Del Potro four times before Friday's match, winning and losing two.

The Australian veteran was able to win the first set 6-4 only to see Del Potro win the following two 7-5, 6-3. Hewitt had a chance to serve out the fourth set when the score got to 5-3 but Del Potro broke back to drag his eight year older opponent to the tie-break. Hewitt fired up in the tie-break, winning six straight points to win 7-2.

Del Potro didn't recover from the close loss of the fourth set. The 24-year-old kept making mistakes, was broken three times and allowed Hewitt the victory.

"He's a great player and a great fighter. For the second round, he's a really difficult player," said Del Potro.

Hewitt will next face 22-year-old Russian Evgeny Donskoy.

Both first seed Novak Djokovic and third seed Andy Murray moved to the next round after easy wins.

In women's singles, No.5 seed Li Na from China took revenge on British talent Laura Robson, who knocked her out at the same round last year. The top Chinese powered 11 aces to dominate the match, beating her 12-year younger opponent 6-2, 7-5 to reach the last 16.

"I have improved a lot, especially with the serves and at the net," said Li.

The first set began with a break from Li. The former French Open champion made full use of Robson's mistake, breaking twice to establish a 4-1 lead. Both players were able to hold their serves in the rest of the games of the first set, which finished with Li's 6-2 win.

Robson played much better in the second set. The British rising star made a break in the second game and found herself leading 3-0. However, three games were not enough to defeat the World No.6. Li shrugged off the pressure to keep her second service game and broke back in the next to get back into the match.

The two players went into the 11th game (5-5). Li awarded herself three straight break points by leading 40-0. Robson saved the first two break points but failed in the third. The match went in favour of Li in the 12th game and the 31-year-old veteran sealed the victory after wasting one match point.

"I'm disappointed about today, for sure, and I thought I could have played a lot better. All in all, I guess it was an average week," said Robson.

Top seed Serena Williams, No.3 Agnieszka Radwanska and No.9 Jelena Jankovic also got into the last 16.