Rafael Nadal had to dig deep before defeating Japan's Kei Nishikori to reach the quarterfinals at Queen's Club on Thursday.

Nadal had torn Roger Federer to shreds in Paris last weekend, but Nishikori, an un-seeded teenager who turned pro just a year ago, pushed the French Open champion all the way.

The Spanish first seed eventually found enough momentum to come through 6-4, 3-6, 6-3 and now plays Croatia's Ivo Karlovic, who beat Fernando Gonzalez 6-3, 7-5, in the last eight.

Nishikori, 18, had never played a singles tournament on grass before arriving at Queen's this year and he admitted that the chance to play his idol was a dream come true.

So it would have been no disgrace if the teenager had been struck by stage-fright in the biggest match of his career, but he gave as good as he got.

A pair of fierce leaping forehands must have impressed a slugger like Nadal and the world number two had to raise his game to take control of the first set.

Nishikori showed no signs of giving in and earned three break points in the second game of the second set. Nadal crushed those opportunities but Nishikori was gaining in belief.

He kept plugging away with some powerful groundstrokes and never let Nadal settle. A break duly arrived in the eighth game, giving him the chance to serve for the set.

It was a massive test of Nishikori's nerve and he passed with honours to set up a final set decider.

But Nadal is a fierce competitor regardless of the occasion. He just redoubled his efforts again and broke to go 3-1 up after sprinting across court to convert a drop shot. Finally Nadal had subdued Nishikori and he was able to serve out the match.

Australian Open champion Novak Djokovic won the all-Serbian clash against Janko Tipsarevic 2-6, 6-1, 6-4.

Djokovic was a set and a break down in his first meeting with Tipsarevic but stepped up the pace in the second set, taking it comfortably before edging through in the decider.

His next opponent is Lleyton Hewitt, who remains on course for a record fifth Queen's title after a 6-4, 6-4 win over Paul-Henri Mathieu.

Hewitt, seeded 11th, got off to a terrible start as he fell 4-1 down, but the former Wimbledon champion is more at home on grass than any other surface and he hit back to level at 4-4.

Mathieu was struggling to cope with Hewitt's relentless pressure and it was no surprise when he was broken again before serving out the set.

Hewitt was on a roll and broke at the start of the second set. Mathieu made no impact on the Australian's serve and the 27-year-old was able to advance.

Andy Murray played through the pain barrier to clinch a gutsy 5-7, 6-1, 6-4 victory over Ernests Gulbis.

Murray needed treatment for thumb, thigh and neck injuries as he struggled to stay on his feet on a treacherous grass-court made extra slick by rain throughout the match.

But the British number one proved a point to the critics who claim he is too quick to let injuries affect him by fighting back from a set down to earn a last eight showdown with reigning champion Andy Roddick.

Roddick, like Hewitt chasing a fifth title, got a lucky break as Mardy Fish withdrew after just one set of their match.

The reigning Queen's champion had just taken the first set on a tie-break when Fish, who fell awkwardly while trying to make a diving volley late in the set, was forced to pull out with a foot injury.

The American had taken the first set thanks to a booming forehand from the baseline that earned him a decisive early mini-break.

But Fish tumbled while trying to return a powerful forehand during that tie-break and he was soon shaking hands with Roddick to concede the tie.

Richard Gasquet, the French fifth seed, won a battle of the grass-court specialists as he saw off Mario Ancic 7-6 (7/5), 6-4. He plays David Nalbandian after the Argentine thrashed last year's runner-up Nicolas Mahut 6-4, 6-1.

AFP