Trailing 3-6 0-3 30-30, Alexandr Dolgopolov drew a chorus of dejected sighs on Centre Court as he walked up to the net to shake hands with Federer.
Earlier Djokovic breezed through to the second round of Wimbledon when opponent Klizan retired during the second set. The crowd was nonplussed, but seemed to hold out hope that seeing Federer do battle with Dolgopolov would lift their spirits. "I'm happy with how that got better".
By simply playing the first point, Federer also drew level with Fabrice Santoro's professional era record of playing in a 70th grand slam tournament. To reach the Promised Land at the hallowed turf of SW19, Federer would have to contend with an extremely challenging half that features the likes of Novak Djokovic, Alexander Zverev, Milos Raonic, Dominic Thiem and Grigor Dimitrov.
Djokovic, the second seed, led 6-3 2-0 when the Slovakian called it a day because of a calf injury.
Djokovic and Federer are the second and third seeds, respectively.
Women's world No 1 Kerber was runner-up previous year and, in the absence of defending champion Serena Williams, the German has the honour of starting the action when she faces America's Irina Falconi before Djokovic takes to the lawns. The 18-time Grand Slam champion will be looking to build on his seven Wimbledon victories, in his bid to overtake the likes of Pete Sampras of the U.S. and William Renshaw of Great Britain, to become the sole leader in terms of the number of Wimbledon men's singles titles won.
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The press release from the police department had few details. "The police have been demoralized in many ways", he said. The number of murders - 320 so far in 2017, compared with 322 at this point past year - has hardly changed.
"You never like to end up a match this way but I heard that Klizan had issues even before walking on the court", said Djokovic.
Federer said: "I felt like there was a bit of a letdown from the crowd".
Federer's next opponent will be the victor of the match between Stefanos Tsitsipas and Dusan Lajovic.
"You would think that somebody who has played well, like Rafa (Nadal) on the clay courts, he would be feeling really good about his chances here and I'm sure he does feel that way".
The 26-year-old Raonic reached the Wimbledon final last year, losing to Andy Murray in straight sets.
For the record that unlucky lucky loser was Klizan's compatriot, Lukas Lacko, ranked 105 in the world, a battler who could have done with the £35,000 cheque for appearing - as well as the thrill of playing a three-time Wimbledon champion on the biggest stage in his sport.