LONDON, England (AFP) — Serena Williams and Andy Roddick, two warhorses of American tennis, endured conflicting Wimbledon fortunes yesterday while Marin Cilic triumphed in the second longest match in tournament history.

Four-time champion Williams clinched a three-set win over China's Zheng Jie to reach the last 16, but thrice runner-up Roddick crashed to a second successive third round defeat, sparking more doubts over his future.

Compatriot Brian Baker, who missed six years of action through a variety of injuries and operations, made the last 16 as his fairytale comeback gathered momentum.

But fellow American Sam Querrey was the fall guy to Cilic's epic efforts, losing in five gruelling sets.

Sixth-seed Williams, playing in her 13th Wimbledon, saw off 25th-seed Zheng 6-7 (5/7), 6-2, 9-7 and will tackle Yaroslava Shvedova of Kazakhstan for a place in the quarter-finals.

Wildcard Shvedova will go into tomorrow's fourth-round tie having made history as the first woman at a Grand Slam to achieve a Golden Set.

She won all 24 points in a first set 6-0 wipeout of Italian 10th seed, and French Open runner-up, Sara Errani on her way to the last 16 for the first time. Shvedova took the second set 6-4.

Roddick, like Williams a former world number one, slumped to a 2-6, 7-6 (10/8), 6-4, 6-3 defeat to Spanish seventh seed David Ferrer and left Centre Court blowing kisses to his fans.

The 29-year-old suffered three agonising final defeats to Roger Federer in 2004, 2005 and 2009, the last of which ended 16-14 in the final set, was Roddick's last memorable campaign at the All England Club.

Baker's Wimbledon debut got even better as he enjoyed a 6-4, 4-6, 6-1, 6-3 victory over France's Benoit Paire.

Cilic, the 16th seeded Croat, beat Querrey, 7-6 (8/6), 6-4, 6-7 (7/2), 6-7 (7/3), 17-15, in a match that lasted five hours and 31 minutes.

It was the second longest match in Wimbledon history, but remains a long way behind the world record 11 hours and five minutes it took John Isner to beat Nicolas Mahut in 2010.

Tenth-seeded American Mardy Fish, playing his first tournament since undergoing a heart operation, beat Belgian wildcard David Goffin, 6-3, 7-6 (8/6), 7-6 (8/6).

Fish will face French fifth seed Jo-Wilfried Tsonga who beat Lukas Lacko of Slovakia, 6-4, 6-3, 6-3.

German 27th seed Philipp Kohlschreiber eased to a 6-2, 6-3, 7-6 (8/6) win over giantkiller Lukas Rosol and will next tackle Baker.

Argentine ninth seed Juan Martin del Potro defeated Kei Nishikor, 6-3, 7-6 (7/3), 6-1, and will face Ferrer.

Defending women's champion Petra Kvitova crushed Varvara Lepchenko of the United States, 6-1, 6-0.

Former world number one Ana Ivanovi clinched a 3-6, 6-3, 6-4 win against Germany's Julia Goerges. Ivanovic will play second seed Victoria Azarenka, a semi-finalist in 2011, who put out world number 178 Jana Cepelova, a Slovak qualifier, 6-3, 6-3.