PHOTOS: Serena gets serious, easy for Murray

With the whiff of a fifth Wimbledon singles title in the air, grass court predator Serena Williams cut down defending champion Petra Kvitova to move ominously into the semi-finals on Tuesday.

The 30-year-old American, who still looks unstoppable when in full flow on a grass court, wheeled out the heavy artillery to crack down 13 aces in a 6-3, 7-5 victory that significantly raised the bar in a disappointing women's tournament.

Fourth seeded Czech Kvitova, who boasts some lethal weaponry of her own, fought fire with fire to stay in contention but was eventually de-throned in a high-quality clash which marked Williams' first taste of life under the Centre Court roof.

"You can't play a defending Wimbledon champion or grand slam champion and not elevate your game," Williams told reporters.

"I had to weed out the riff raff and just get serious," she added.

The men's draw finally got back on track as the five fourth round matches were completed 24 hours later than scheduled despite the best efforts of a non-existent British summer.

For a change it was all rather tame for home favourite Andy Murray who dispensed with the theatrics to ease past Marin Cilic into the quarter-finals for a fifth straight year.

On the day the women's last eight normally take centre stage at the grass court grand slam, Murray returned at midday to finish off Croatian Cilic 7-5, 6-2, 6-3 to fuel hopes of a first home men's winner at the championships since 1936.

The fourth seed was again held up by rain for a while but took advantage of a bright spot in the murky skies to dispatch Cilic with a minimum of fuss.

Murray will face Spain's David Ferrer in the quarter-finals in a repeat of their Roland Garros clash after the seventh seed thrashed Argentina's Juan Martin del Potro 6-3, 6-2, 6-3.

Florian Mayer and Philipp Kohlschreiber continued Germany's impressive showing at the tournament as they both reached the quarter-finals - matching the feat of Sabine Lisicki and Angelique Kerber who were playing each other later.

Mayer finished off Frenchman Richard Gasquet 6-3, 6-1, 3-6, 6-2 and will face defending champion Novak Djokovic on Wednesday, while Kohlschreiber ended the run of American qualifier Brian Baker to reach his first grand slam quarter-final in which he will play French showman Jo-Wilfried Tsonga.

Tsonga was the last player through, reeling in American Mardy Fish to win 4-6, 7-6, 6-4, 6-4 in a stop-start tussle.

With nine of the past 12 women's singles titles going to either Serena Williams or sister Venus, the scratching of another name on the trophy, as Kvitova did last year, is regarded as a personal affront by the siblings.

While the regular WTA tournaments no longer fire Serena's engines, she comes alive at the business end of Wimbledon and after some patchy performances she is now favourite to reclaim family honour on Saturday.

One point said it all about her warrior instinct.

After saving a set point at 4-5 in the second set, she then drew level at 5-5 with a point of raw brutality.

With Kvitova stranded at the net, Serena had open water either side of the Czech but elected instead to belt the ball straight at her opponent. Amazingly Kvitova got it back but the American swatted away the loose ball.

Two games later it was all over - Serena letting out a roar that nearly took the roof off Centre Court.