WIMBLEDON, England -- Top-seeded Lleyton Hewitt and Venus Williams bolstered their status as title favorites by winning easily in straight sets Monday to reach the quarterfinals on a chilly, rainy day at Wimbledon.
Tim Henman, meanwhile, rallied from a break down in the fifth set to maintain his hopes of becoming the first British player to win the men's title since 1936.
Henman, suffering from an upset stomach and receiving smelling salts from the trainer, pulled out a 7-6 (5), 6-7 (2), 4-6, 6-3, 6-2 win over Switzerland's Michel Kratochvil in a rain-interrupted match lasting more than four hours.
"I can't quite figure out how I won," Henman said. "I'm just so happy to still be alive."
Hewitt swept Russia's Mikhail Youzhny 6-3, 6-3, 7-5 on Centre Court to make the final eight at Wimbledon for the first time. The Australian hasn't dropped a set in four matches.
"I haven't used a lot of energy so far," he said. "I still feel I'm able to go up another gear if I have to."
Williams, the two-time defending champion, routed 35th-ranked Lisa Raymond 6-1, 6-2 in just 47 minutes in the day's opening match on Court 1 for her 18th straight singles win at Wimbledon.
Her sister, second-seeded Serena Williams, also advanced by beating Chanda Rubin 6-3, 6-3 in a rain-interrupted match. Williams led 4-3 in the second set when play was suspended. When the match resumed 1:50 later, Williams finished it off in seven minutes.
With two more wins apiece, the Williams sisters will meet in their third Grand Slam final in 10 months.
No. 4 Monica Seles, who could meet Venus Williams in the semis, beat Tamarine Tanasugarn 6-2, 6-2. No. 7 Jelena Dokic, a semifinalist in 1999, lost 6-4, 7-5 to No. 11 Daniela Hantuchova.
No. 3 Jennifer Capriati split the first two sets with Eleni Daniilidou when the match was suspended by darkness. It will resume Tuesday.
Meanwhile, three South Americans reached the men's quarters for the first time in the Open era, and the tournament was hit by its first rain delays of the fortnight.
The day's greatest drama was provided by fourth-seeded Henman, a losing semifinalist three of the past four years. He came in as the pre-tournament betting favorite, carrying immense national expectations to become the first British male champion since Fred Perry in 1936.
Henman was in serious danger of going out to 45th-ranked Kratochvil, who had never won a match at Wimbledon before this year. But the Swiss player, hurt by 17 double faults and 57 unforced errors, failed to capitalize when he had the match in his hands.
Kratochvil double-faulted three times while serving for the first set at 5-4 and lost in a tiebreaker. But he came back strong, took the next two sets and looked in charge.
Henman, looking listless in the fourth set, called for ATP trainer Bill Norris, who gave him smelling salts and massaged his legs on three changeovers. Kratochvil also received treatment from Norris for a scraped knee.
The Swiss player went up a break, 2-1, in the fourth but couldn't take advantage as Henman broke twice to send the match into the fifth set. Kratochvil broke to go up 2-0 but again faded, with Henman winning six straight to close out the 4:13 contest.
When Kratochvil missed a forehand return on the second match point, Henman held up his arms and looked skyward -- more in relief than celebration.
Henman said he had never considered pulling out.
"I just had to keep fighting, the adrenaline got going and I started to feel better," he said.
Williams, who wore a white bandage on her left knee and had her right wrist taped, was much sharper than Saturday, when she dropped the first set against 110th-ranked Maureen Drake of Canada.
"It's definitely nice I've won the tournament before and have the experience," said Williams, the only former champion left in the women's draw. "I know what it takes to win here. I have a lot going for me with that."
Raymond, a 28-year-old American who is known primarily as a doubles specialist, couldn't cope with Williams' power game. Williams had 20 winners, 16 more than Raymond.
"I'm just trying to impress as the tournament goes on, just trying to get my feet moving," Williams said. "I'm feeling better about keeping my unforced errors down, just trying to play some controlled tennis."
Williams and Hewitt advanced on a day when all 16 men's and women's fourth-round matches were scheduled. Only 13 were completed.
After a completely dry first week, the start of play on the outside courts was delayed by 40 minutes, and then all matches were suspended in late afternoon for nearly two hours.
Fans were bundled up in sweaters and rain jackets, with temperatures around 62 degrees (17 c) and a brisk wind.
Hewitt had faced Youzhny the week before Wimbledon at a tournament in the Netherlands, winning 7-6 in the third. But it was a mismatch this time as Hewitt outplayed him in all phases.
Hewitt played a controlled match, while Youzhny went for broke and had more winners (29 to 19) and unforced errors (42 to 22) than his opponent.
Hewitt broke five times. Youzhny broke only once, with Henman serving for the second set at 5-2. Hewitt broke back in the next game to take the set. In the third set, Hewitt saved two break points at 3-3 and broke in the 12th game to end the match.
Hewitt will next meet 18th-seeded Sjeng Schalken, who downed Jan Vacek 6-2, 7-5, 7-5.
In another early men's match, 20-year-old David Nalbandian beat Wayne Arthurs 6-4, 7-6 (4), 2-6, 7-6 (7) to become only the second Argentine to reach the quarterfinals at Wimbledon. Guillermo Vilas was a losing quarterfinalist in 1975 and 1976.
Arthurs, who hadn't dropped his serve all tournament, lost despite serving 35 aces and being broken only once. He finished with 116 aces in four matches.
Two other South Americans joined Nalbandian in the next round -- Nicolas Lapentti of Ecuador, who beat France's Arnaud Clement 3-6, 7-5, 2-6, 7-5, 6-3; and Brazil's Andre Sa, who downed Feliciano Lopez of Spain, 6-3, 7-5, 4-6, 6-3.
Lapentti is the only Ecuadorian to get this far other than Andres Gomez, who reached the 1984 quarters. Sa is the second Brazilian to do so -- after Gustavo Kuerten in 1999.
In an early women's match, Russia's Elena Likhovtseva downed No. 19 Magdalena Maleeva 6-3, 6-4 to reach her first Wimbledon quarterfinal.
No. 6 Justine Henin, last year's losing finalist, edged No. 12 Elena Dementieva 7-6 (4), 7-6 (5), while No. 9 Amelie Mauresmo was a 6-2, 6-2 winner over American Laura Granville. l