Serena packs off defending champion Kvitova

By Martyn Herman

LONDON (Reuters) - Scenting a fifth Wimbledon singles title, grasscourt predator Serena Williams mowed down defending champion Petra Kvitova to move ominously into the semi-finals for the eighth time on Tuesday as the championships again battled the elements.

The 30-year-old American, who still looks unstoppable when in full flow on the lawns, 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.

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

For a change it was all rather tame for home favorite Andy Murray who dispensed with the theatrics to ease past Marin Cilic 7-5 6-2 6-3 to reach the last eight for a fifth straight year.

Williams was ruthless against fourth seed Kvitova, who boasted some lethal weaponry of her own.

Czech Kvitova fought fire with fire to stay in touch with the American powerhouse 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."