Andy Murray
Murray seals another straight sets victory.Getty

Andy Murray took another step closer to defending his Wimbledon crown after defeating Kevin Anderson in straight sets to seal a spot in the quarter-finals.

The Brit is yet to drop a single set as he sealed a 6-4 6-3 7-6 (8-6) victory over his South African opponent under the roof of Centre Court after a brief rain delay in the second set.

Murray faces the challenge of either Grigor Dimitrov or Leonardo Mayer in the next round.

Murray was forced into a tie-break at set point after Anderson came out fighting following the rain delay but maintained his composure to seal a quarter final spot for the seventh time in his career to continue his quest to become the first man to win back to back titles at SW19 since Fred Perry in 1936.

Murray sealed the opening set within 45 minutes as he comfortably dealt with Anderson's powerful serve - the imposing 28-year-old's biggest strength – to take an early advantage.

Murray initially struggled to find his rhythm in the opening stages of the second but just as the clouds above south west London began to darken he found it once again, forcing Anderson to over hit a forearm after the Scot's seventh chance of the opening game.

Just as Murray broke again to take a 3-0 advantage, play was halted and the subsequent break provided Anderson with the resolve to claw the contest back to 3-3 after breaking his opponent.

It was to be a short-lived resurgence however, as Murray proceeded to break his opponent for a fourth time en route to sealing the second set.

The Scot needed a tie breaker to clinch the third after he slipped at 4-3 but saw off the challenger with a backhand into the corner of the court to seal victory.