Former champions Justine Henin-Hardenne and Lindsay Davenport [Images] remained on course for a quarter-final showdown with lopsided second-round victories at the US Open on Thursday.

Henin-Hardenne crushed American teenager Vania King 6-1, 6-2 and Davenport overwhelmed Croatia's Jelena Kostanic 6-0, 6-0 on a breezy upset-free day under clear skies at Flushing Meadows.

Top seed Amelie Mauresmo of France [Images] and Russian third seed Maria Sharapova [Images] also marched on with straight-sets victories.

While the top women progressed without a hitch, Andre Agassi [Images] will be in the spotlight later when he faces eighth seed Marcos Baghdatis in the night session.

Second seed Rafael Nadal [Images] needed nearly three hours to subdue Peru's Luis Horna 6-4, 4-6, 6-4, 6-2 while former champion Lleyton Hewitt [Images] advanced with a 6-4, 6-2, 6-2 victory over Jan Hernych of the Czech Republic.

Twice former women's champion Serena Williams [Images] defeated 17th seed Daniela Hantuchova [Images] 7-5, 6-3 and was joined in the third round by Russians Elena Dementieva, Nadia Petrova and Svetlana Kuznetsova, and Swiss Patty Schnyder.

Second seed Henin-Hardenne, the 2003 champion, blasted 22 winners in her match with King.

The Belgian, who swept past Italy's [Images] Maria Elena Camerin 6-2, 6-1 in the opening round, said she did not mind having an easy time early in the event.

"A win like this is better because physically you're not going to find your limits, which is good," said the five-times Grand Slam champion, who will next face Ai Sugiyama of Japan [Images].

"I thought it was a lot closer than 6-1 6-2," said the 17-year-old King, who was set to sing the national anthem in the traditional ceremony which starts the evening session.

"I made her play a lot of balls but I didn't convert a lot of the points I should have."

Davenport blitzed Kostanic in 40 minutes, showing no sign of the shoulder injury that forced her to retire during the final of last week's event in New Haven.

"It's feeling better," said the 1998 champion. "It's funny because yesterday it was really sore so I'm not really sure the rhyme or reason for it."

The 30-year-old Davenport uncharacteristically ventured to the net during the match but claimed she was not trying to quicken the points to save wear and tear on her shoulder.

"She has the type of game that I had more time to be able to do that," she said. "I wasn't trying to make the points shorter, I was trying just to be aggressive."

Next up for 10th seed Davenport will be Katarina Srebotnik of Slovenia or Russian Ekaterina Bychkova.

Mauresmo had a tough time with American Meghann Shaughnessy before winning 6-4, 6-3, while Sharapova dismissed France's Emilie Loit 6-0, 6-1 in 52 minutes.

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