A day after Roger Federer led a mass exodus of high-seeded players and favorites, the top-ranked man and woman sailed past the wave of upsets and advanced to the third round with straight-set victories.
Djokovic defeated American qualifier Bobby Reynolds 7-6 (2), 6-3, 6-1 under the retractable roof on Centre Court. A few hours earlier, Williams dismissed 19-year-old Caroline Garcia of France 6-3, 6-2.
In fact, after Wednesday's nonstop string of stunners, there wasn't a surprise to be had at the All England Club. The highest-seeded player to lose was No. 17 Milos Raonic of Canada, and there were just two injury retirements compared with seven Wednesday.
Instead, there was the familiar sight of covers being pulled over the courts as rain came to the All England Club for the first time this week, forcing the roof to close and a number of afternoon matches to be suspended until Friday.
With Rafael Nadal and Federer knocked out in the first three days, Djokovic also faced surprisingly stiff resistance from Reynolds in the first set. However, he dominated the tiebreaker and had little trouble from there, breaking Reynolds twice in the second and third sets.
In the process, Djokovic made this the worst Wimbledon for American men in 101 years. Reynolds' loss means none of the 11 American men in the tournament advanced past the second round, the first time that's happened since 1912. There were no American men in the tournament that year, although none reached the third round in 1911 either.
Williams is still the favorite in the women's draw, however, and will now go from playing an opponent 12 years her junior to facing one 11 years her senior.
Next up for the 31-year-old American is Japan's Kimiko Date-Krumm, who at 42 became the oldest woman to reach the third round at Wimbledon in the Open era. Date-Krumm beat Alexandra Cadantu of Romania 6-4, 7-5 to advance this far at Wimbledon for the first time since 1996, when she went to the semifinals.
"I have so much respect for her," said Williams, who herself became the third-oldest woman in the Open era to win a Grand Slam tournament when she captured this year's French Open. "I think she's so inspiring to be playing such high level tennis at her age. And she's a real danger on the grass court, I know that. I definitely will have to be ready."
Date-Krumm is the second-oldest woman to have won a match at Wimbledon after Martina Navratilova, who was 47 when she reached the second round in 2004. She took a 12-year break from tennis before returning in 2008.
"I don't know how she's able to do so well," said Williams, adding she doesn't expect to be around for another 10 years. "I didn't see myself playing at 31. I definitely do not see myself playing at 42."
Age certainly doesn't seem to be slowing her down.
Williams broke twice in each set to extend her career-best winning streak to 33 matches as she aims for a sixth Wimbledon title. Her two main rivals, Maria Sharapova and Victoria Azarenka, were among those eliminated Wednesday.
Last year's runner-up, Agnieszka Radwanska, also breezed into the next round with a 6-1, 6-3 win over Mathilde Johansson of France, which had to be completed under the roof.
In the men's draw, seventh-seeded Tomas Berdych and No. 8 Juan-Martin Del Potro advanced in straight sets. Berdych, the 2010 runner-up, beat Daniel Brands of Germany 7-6 (6), 6-4, 6-2. Del Potro rallied from a break down in the second set to oust Jesse Levine of Canada 6-3, 7-6 (7), 6-3.
Fourth-seeded David Ferrer was among those who will wait until Friday to play, as his match against fellow Spaniard Roberto Bautista Agut was postponed. A back-and-forth five-setter between No. 29 Grigor Dimitrov and Grega Zemlja was suspended overnight, with Zemlja up 9-8 in the fifth.
No. 6 Li Na of China looked in trouble for a while before overcoming a poor second set to beat Simona Halep of Romania 6-2, 1-6, 6-0. Other seeded players to win included No. 11 Roberta Vinci and No. 14 Samantha Stosur. Bernard Tomic of Australia advanced by defeating American James Blake 6-3, 6-4, 7-5. Tomic's father and coach, John Tomic, is barred from tournaments after allegedly assaulting his son's hitting partner.
The two injury retirements were Michael Llodra, who quit with a hamstring problem after losing the first set 7-5 against 23rd-seeded Andreas Seppi of Italy, and Paul-Henri Mathieu, who retired while trailing 6-3, 5-1 against Feliciano Lopez of Spain.
The nine retirements or walkovers of the second round in singles play broke the record for a round at Wimbledon in the Open era. The International Tennis Federation said eight players quit in the first round in 2008.
It equaled the record for a Grand Slam tournament, as nine players withdrew or retired from the first round at the 2011 U.S. Open.