Federer, Djokovic get free passes

Roger Federer and Novak Djokovic barely had to break sweat to make winning starts at Wimbledon as their injury-hit opponents retired hurt from their first round matches on Tuesday.

Federer is chasing a record eighth Wimbledon title and he was already well on top at the start of his 19th All England Club campaign when Alexandr Dolgopolov was forced to quit with an ankle injury.

The world number three raced into a 6-3, 3-0 in 43 minutes on Centre Court before the Ukrainian limped off.

Federer, who hit his 10,000th career ace in the eighth game of the first set, will face either Dusan Lajovic of Serbia or Greek qualifier Stefanos Tsitsipas for a place in the last 32.

"It feels great to be back on Centre Court," said Federer, who recorded his 85th match win at Wimbledon, passing the mark he shared with Jimmy Connors.

Djokovic, a three-time Wimbledon champion, was leading 6-3, 2-0 when Slovakian world number 47 Martin Klizan retired after just 40 minutes on Centre Court due to a calf problem.

The 30-year-old Serb will face Adam Pavlasek of the Czech Republic for a place in the last 32.

It was the kind of trouble-free first round Djokovic would have been hoping for after the most turbulent period of his career, the 12-time major winner losing in the Australian Open second round and the French Open quarter-finals.

With defending champion Serena Williams sidelined while she prepares to give birth to her first child, the race to win the women's title is the most wide open in a generation.

World number one Angelique Kerber, the 2016 Australian and US Open winner, is among the favourites after reaching last year's final, which she lost to Serena.

The German has failed to maintain that form this season and her poor run culminated in an embarrassing French Open first round loss to Ekaterina Makarova last month.

But the top seed showed glimpses of her best form as she saw off American qualifier Irina Falconi 6-4, 6-4 in 87 minutes on Centre Court.

Milos Raonic advanced to the second round with a 7-6 (7/5), 6-2, 7-6 (7/4) win against Jan-Lennard Struff.

Argentina's Juan Martin Del Potro, a 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.

Australia's Bernard Tomic said he had lost his "respect" for tennis following his lacklustre 6-4, 6-3, 6-4 loss to Mischa Zverev.

French 22nd seed Richard Gasquet slumped to a 6-3, 6-4, 5-7, 6-2 loss against Spain's David Ferrer.

Former French Open champion Garbine Muguruza, the 14th seed, defeated Russia's Ekaterina Alexandrova 6-2, 6-4.

Match of the day

GAVRILOVA (20) V MARTIC
The game of the day was a frenetic match between 20th seed Daria Gavrilova and Petra Martic, which the qualifier won 6-4, 2-6, 8-10. Gavrilova lost the first set, but comfortably won the second before a final set that almost seemed like it would never end. In the end, the 26-year-old Croat came out on top after a gruelling 18 games in the final set of the two-hour-thirty-five-minute match.