Djokovic, Federer 'walkover' to next round
London: Former champions Roger Federer and Novak Djokovic both reached the second round at Wimbledon without completing matches after their opponents retired.
Third seed Federer led 6-3 3-0 when Ukrainian Alexandr Dolgopolov quit with an ankle injury after 43 minutes.
Federer has now won more men's matches than anyone else at Wimbledon with 85.
The Centre Court crowd had already seen second seed Djokovic progress after a calf injury saw Martin Klizan pull out at 6-2 2-0 down on 40 minutes.
"You never like to end up a match this way," said Djokovic.
"I heard that Klizan had issues even before walking on the court. You could see he wasn't moving. Once the ball was a couple of feet away from him, he let it go."
The Serb, 30, goes on to face Czech Adam Pavlasek in the second round on Thursday as he pursues a third Wimbledon title.
Seven-time champion Federer took his first step towards a record eighth victory at the All England Club. Jimmy Connors has 84 wins, Boris Becker 71 and Pete Sampras 63.
Djokovic needed just 40 minutes to reach the second round at Wimbledon after Martin Klizan retired in the second set. Djokovic, the second seed, led 6-3 2-0 when the Slovakian approached the net and called it a day. The Serb goes on to face Czech Adam Pavlasek in the second round on Thursday.
Sixth seed Canadian Milos Raonic, last year's runner-up, saw off Germany's Jan-Lennard Struff 7-5 (7-5) 6-2 7-6 (7-4) in his opening match.
Argentina's Juan Martin Del Potro, a Wimbledon semi- finalist in 2013, defeated Australian Thanasi Kokkinakis 6-3, 3-6, 7-6 (7/2), 6-4 as the 29th seed moved towards a potential third round classic against Djokovic.
Stan Wawrinka, the owner of one championship from each of the other three major tournaments, and the French Open runner-up just three weeks ago, was bothered by his left knee and lost 6- 4, 3-6, 6-4, 6-1 to Daniil Medvedev at Centre Court in the first round on Monday.