The 12-times grand slam victor also called for fifth-set tiebreakers to be introduced at the tennis showpiece after completing the men's quarter-final line-up with a 6-2 7-6 (7-5) 6-4 victory over unseeded Frenchman Adrian Mannarino. The Grand Slam supervisor and assistant referee didn't believe that there was either.
But the Spaniard's defeat by Muller lasted 4 hours 48 minutes and made it impossible for the Serb's match to be completed before dark.
With Wade, the 1977 champion, sitting in the Royal Box, Konta prevented Halep from rising to No. 1 by beating her 6-7 (2), 7-6 (5), 6-4. Magdalena Rybarikova and CoCo Vandeweghe were to follow. Previously these two players met each other in one match at Wimbledon past year.
It was, as so much of the match had been, the favourite's backhand against the lefty's forehand but this time it went the way the crowd had expected, Mannarino finding the net as Djokovic marched on to the last eight.
That match lasted nearly five hours, with 28 games played in the fifth set.
Meanwhile the new French Open champion Jelena Ostapenko was on the 1,000-seater Court 12 show court. Play on the outside courts starts at 11:30am, or 11:00am for junior matches.
Djokovic survives injury, blasts state of Wimbledon Centre Court
"But I didn't feel like it was unsafe", said Federer, who has won seven of his record 18 major titles at Wimbledon.
However late in the day it was determined that the match would be set back to Tuesday, and moved to Centre Court where it will begin at the earlier than usual time of midday. The victor will go through to face Czech Tomas Berdych in the quarter-finals on Wednesday.
He broke in the third game of the third set, but then came a sight to worry the Djokovic fans as he called on the trainer to look at an injury in his right arm. This is the second time Djokovic has defeated Mannarino in Wimbledon. The opening match on Centre Court was due to start at noon, so the roof was closed for the first time this year.
Adrian Mannarino had a good chance to snap this part of the game, but Joker found the strength to overcome this and came back from behind, doubling the lead.
To get to what would be her ninth final at the All England Club, the 10th-seeded Williams will need to win Thursday against No. 6 Johanna Konta, the first British woman in the Wimbledon semifinals since Virginia Wade was the runner-up in 1978.
"Finally when the [Nadal Muller] match was over, we thought, Okay, we have two and a half hours, we can go to Centre Court".
Two Amarnath pilgrims among six feared dead in militant attacks
Immediately after the militant attack, police, CRPF and army men and officials reached the spot to take stock of the situation. State minister Naeem Akhtar said, " First time pilgrims have been targeted and this is a dark chapter in Kashmir's history".