Ons Jabeur plays a return to Spain's Garbine Muguruza during the women's singles third round match in London. AP
Belarus second seed Aryna Sabalenka faces 18th seeded Elena Rybakina. Sabalenka, yet to make a quarter-final of a Slam had 21 aces over three rounds, one fewer than Russian-born Rybakina.
Former world number one Karolina Pliskova, the eighth-seeded Czech has also fired 22 aces and she faces unseeded Russian Liudmila Samsonova.
Samsonova, ranked 65, has made the most of her wild card to register her best ever performance at a Slam.
Having won the Berlin grass court tournament as a qualifier in the run-up to Wimbledon, the 22-year-old is on a 10-match win streak.
Wimbledon is set to start in London on June 29, but the continuing spread of the virus has caused havoc with the sporting schedule and the grass-court Grand Slam could be the next major event to be delayed.
Federer had appeared in the singles rankings every week since he made his debut at age 16 in September 1997, tied for 803rd, and held the record for most time at No.1 until Djokovic broke it.
Roger Federer faced serious questions over his future on Wednesday after crashing out of Wimbledon in the quarter-finals, just five weeks shy of his 40th birthday. Eight-time Wimbledon champion and 20-time Grand Slam title winner
Unheralded Karolina Muchova saved a match point as she stunned world number two Aryna Sabalenka to reach the French Open final on Thursday, while Iga Swiatek hopes to stay on course for a third Roland Garros title.
India eventually dismissed Australia for 469 after lunch, fast bowler Siraj leading the way with 4-108. Smith had batted in relatively sedate fashion to reach 95 not out off 227 balls overnight while Head blazed his way to an unbeaten 146 off just 156 balls.
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