Switzerland's Roger Federer returns a forehand to France's Arnaud Clement, on the fifth day of the Wimbledon Tennis Championships, at the All England Lawn Tennis Club in southwest London. Federer won 6-2, 6-4, 6-2. (AFP)

LONDON (AFP) – Roger Federer looked back to his best as he booked his place Friday in the second week of Wimbledon as Andy Roddick and Venus Williams also powered into the fourth round.

Exhausted record-breaker John Isner tumbled out in straight sets as Kim Clijsters and Justine Henin set up a fourth-round clash of the Belgian comeback queens.

Meanwhile third seed Novak Djokovic set up a tie with the in-form Lleyton Hewitt.

Men's defending champion Federer finally got through a match without dropping a set when he saw off Frenchman Arnaud Clement.

Federer had dropped three sets during unusually sloppy displays against unheralded pair Alejandro Falla and Ilija Bozoljac in the previous two rounds.

But the Swiss top seed gave a sublime display to set up a clash with Austrian 16th seed Jurgen Melzer.

"I've had a tough first week," Federer said. "It's been tough mentally but I'm excited I'm still in the tournament rather than watching Wimbledon from the couch at home."

Roddick, the man he beat in last year's dramatic final, was made to work as he booked his fourth round place with a 7-5, 6-7 (5/7), 6-3, 6-3 win against Germany's Philipp Kohlschreiber.

"I got a little complacent because he was being the aggressor in the first couple of sets but the last two sets were real good," the American number one said.

"I've had a couple of rough matches here early on but I'm just glad to get through."

His compatriot Isner dragged his battered body back to the All England Club after his epic, record-shattering encounter with French qualifier Nicolas Mahut.

The 23rd seed was clearly feeling the strain, losing his second round match 6-0, 6-3, 6-2 to Thiemo de Bakker of the Netherlands.

Less than 20 hours earlier, Isner eventually defeated Mahut 6-4, 3-6, 6-7 (7/9), 7-6 (7/3), 70-68 after 11 hours and five minutes and an incredible 183 games.

"I was just low on fuel out there. I didn't really have a chance," Isner said.

"It was brutal. Things were looking pretty bleak right from the get-go.

"I have never been this exhausted before."

In the women's draw, five-times Wimbledon champion Williams saw off Russian seed Alisa Kleybanova, 6-4, 6-2.

"These players I'm playing against, I definitely feel I'm holding them at bay," the world number two said.

She faces Australia's in-form Jarmila Groth in round four.

Meanwhile Belgian duo Clijsters and Henin set up a fourth-round encounter after they both saw off Russian seeds in straight sets.

The former world number ones are both seeking to add the Wimbledon crown to their already impressive list of titles after coming out of retirement.

On Clijsters' last appearance at Wimbledon in 2006, she was beaten by Henin in the semi-finals.

"To play each other again in a Grand Slam, it's something we couldn't expect a year ago. It's going to be interesting, very exciting," Henin said.

Eighth seed Clijsters brushed aside 27th seed Maria Kirilenko 6-3, 6-3 on Court Two.

Henin, the 17th seed, made her first appearance back on Centre Court since coming out of retirement. She last contested Wimbledon in 2007.

She defeated 12th seed Nadia Petrova 6-1, 6-4.

Serbian men's third seed Djokovic saw off Spain's Albert Montanes, the 28th seed, in straight sets.

He next faces Australia's 2002 Wimbledon winner Hewitt, who beat Gael Monfils, also in straight sets.

Lu Yen-Hsun became the first man from Taiwan to make it through to a Grand Slam fourth round when his German opponent Florian Mayer pulled out at 6-4, 6-4, 2-1 down.

Tomas Berdych of the Czech Republic also made it through, as did Melzer and Daniel Brands.

Russian 13th seed Mikhail Youzhny was beaten in five sets by Frenchman Paul-Henri Mathieu in a delayed second round match.

In the women's draw, Serbian fourth seed Jelena Jankovic beat Ukraine's 28th-seeded Alona Bondarenko 6-0, 6-3. Another win would make it her best ever Wimbledon run.

Elsewhere, French 11th seed Marion Bartoli, the beaten finalist in 2007, went through, as did fellow seed Vera Zvonareva of Russia and Bulgaria's Tsvetana Pironkova.