Defending champion Carlos Alcaraz keeps himself on course for a third Wimbledon title in a row by overcoming Jan-Lennard Struff to reach the fourth round.

However, the Spaniard will have to cut out his errors if he is to become just the fifth man in the Open era to perform that feat.

Defending Wimbledon champion Carlos Alcaraz was given another tough litmus test by plucky German Jan-Lennard Struff but the second seed battled his way to a 6-1 3-6 6-3 6-4 victory and reached the fourth round on Friday.