Ugo Humbert knocked off the men's singles third seed at Wimbledon ©Getty Images

Third seed Casper Ruud was knocked out of Wimbledon by Ugo Humbert - despite the Frenchman arriving on the grass court without a racquet - while two-time champion Sir Andy Murray is also out.

Humbert did eventually get the necessary equipment, and the uncertainty may explain his slow start, but the left-hander came from behind to win 3-6, 6-2, 7-5, 6-4 and reach round three.

Humbert broke Ruud's serve six times en route to victory in London.

Ruud, who reached the French Open final earlier this month, is the highest-ranked player to be knocked out of the men's singles so far.

The Norwegian had not won a main-draw singles match at Wimbledon before this week, however, so a second-round exit still represents a modicum of progress.

Home favourite Murray, who also won an Olympic gold medal at Wimbledon during London 2012, was no match for John Isner's booming serve.

The American's serve was never broken, but he did need four sets to earn the second-round victory.

Isner won 6-4, 7-6, 6-7, 6-4.

Novak Djokovic, the top seed and defending champion, beat Australian Thanasi Kokkinakis 6-1, 6-4, 6-2.

Fellow Serbian Miomir Kecmanović awaits in round three.

This could be Djokovic's last Grand Slam for 11 months as the he is not vaccinated against COVID-19, so cannot enter the United States at present.

Having been deported from Australia earlier this year over his vaccination status and visa application, Djokovic is set to miss next year's Australian Open as well as the 2022 US Open.

Twenty-year-old Italian Jannik Sinner, seeded 10th, will play Isner following a four-set win against Swede Mikael Ymer.

Spaniard Carlos Alcaraz, 19, needed five sets to get through his first-round encounter but saw off Dutch player Tallon Griekspoor in straight sets today.

Three top-10 seeds were eliminated in the women's singles - Anett Kontaveit, Garbiñe Muguruza and Emma Raducanu.

Estonia's Kontaveit was stunned by Jule Niemeier, in the latter's first-ever top-10 win.

The German triumphed 6-4, 6-0 in less than an hour, playing in just her second Grand Slam.

Jule Niemeier earned the biggest win of her career today ©Getty Images
Jule Niemeier earned the biggest win of her career today ©Getty Images

France Carolina Garcia beat home favourite Raducanu - the reigning US Open champion - 6-3, 6-3.

Garcia and Niemeier are both into round three.

Muguruza's first-round match carried into today and the 2017 champion lost in straight sets to Belgian Greet Minnen.

Former winner Angelique Kerber of Germany and Tunisian third seed Ons Jabeur both reached round three in straight sets.

The same can be said for Greek Maria Sakkari - seeded fifth - and Latvia's Jelena Ostapenko, the 2017 French Open champion and 12th seed.

Lesia Tsurenko is also through to round three after winning an all-Ukrainian affair versus Anhelina Kalinina.