LONDON: Andy Murray took another step closer to ending Britain's agonising 77-year wait for a men's Wimbledon champion on Monday as Jerzy Janowicz and Lukasz Kubot guaranteed Poland a semi-final place.

British second seed Murray survived a second set wobble to carve out a 6-4, 7-6 (7/5), 6-1 win over Russian 20th seed Mikhail Youzhny to reach the quarter-finals.

Murray, the runner-up to Roger Federer in 2012, will face Spain's Fernando Verdasco for a place in the semi-finals.

The Scot has an 8-1 winning record over unseeded Verdasco, a former top-10 player.

Murray had to battle back from 2-5 down in the second set to quell the threat posed by Youzhny, who needed treatment on a shoulder injury after one game of the third set.

Murray put in an impressive serving performance, firing 15 aces and hitting 45 winners past the experienced Russian.

“It was a tough match, the first couple of sets especially. He also had a few chances at the beginning of the third set as well but once I got ahead in the third I concentrated very hard not to let him back in like I did in the second set,” said Murray.

The Scot said he wasn't getting carried away by the national hysteria as he tries to become Britain's first champion since Fred Perry in 1936.

He is wary of becoming another shock Wimbledon victim, like Roger Federer and Rafael Nadal.

“Roger's lost and Rafa's lost. All these guys are better players than me and have achieved a lot more than me and so if they can lose so can I. I just concentrate on the next one and try and get through it.”Verdasco, a former world number nine who now stands at 54 in the world and is playing his 41st successive major, reached his first Wimbledon quarter-final with a 6-4, 6-4, 6-4 win over unseeded Frenchman Kenny De Schepper.

Davis Cup teammates Janowicz and Kubot set-up the first ever all-Polish quarter-final.

Janowicz, the 24th seed, defeated Austria's Jurgen Melzer, 3-6, 7-6 (7/1), 6-4, 4-6, 6-4 on the back of 16 aces and 34 winners as he reached his first Grand Slam quarter-final.

The 22-year-old was joined in the last eight just moments later by 31-year-old Kubot, the lowest-ranked player left at 130 in the world, who defeated France's 111th-ranked Adrian Mannarino, 4-6, 6-3, 3-6, 6-3, 6-4.

The last Pole to reach the last-eight at Wimbledon was Wojtek Fibak in 1980.

“It's unbelievable what is going on right now. We have two players in the quarter-finals and a woman in the quarter-finals. I think this is by far the best what possibly could happen to Polish tennis,” said Janowicz.

Spanish fourth seed David Ferrer reached the quarter-finals for the second successive year by firing 53 winners in his 6-7 (6/8), 7-6 (7/3), 6-1, 6-1 win over Croatia's unseeded Ivan Dodig.

He goes on to tackle Argentine eighth seed Juan Martin del Potro who reached his first Wimbledon quarter-final with a 6-4, 7-6 (7/2), 6-3 win over Andreas Seppi, the 23rd seeded Italian.

However, Del Potro, the 2009 US Open champion, admitted that he is still being bothered by knee trouble.

“It bothers me a lot. I couldn't extend 100 percent the knee. The tapes for today helped me to be careful in some movements. But it is not enough,” said Del Potro.

The 31-year-old Ferrer, who was defeated in the French Open final by Nadal last month, will be playing in his seventh consecutive Grand Slam quarter-final.

Ferrer insists that the ankle injury which he has carried into Wimbledon will not be a problem.

“There is a little bit of pain, but it's normal. It's impossible to play without any pain,” he said.

Later Monday, top seed Novak Djokovic, the 2011 champion,beat 2009 semi-finalist Tommy Haas, the 35-year-old German 13th seed who was bidding to become the oldest Wimbledon quarter-finalist since Tom Okker in 1979.

Novak Djokovic continued his stroll through the top half of the Wimbledon draw with a 6-1 6-4 7-6(4) victory over Tommy Haas to reach the quarter-finals on Monday.

The Serb, bidding for a second title at the All England Club, is yet to drop a set, although he did have a hiccup when he trailed in the second against 35-year-old German Haas.

Haas, blown off court in a 25-minute opening set, raised his game to break in the fifth game of the second set but Djokovic hit back to level at 4-4 with a crosscourt backhand winner.

Normal service was soon resumed as Djokovic took the second set and moved 5-2 ahead in the third but Haas managed one last counter-attack to stretch the contest into a tiebreak.

With the light fading Djokovic slammed the door shut to roll on.

The victory gave Djokovic, who has yet to drop his serve in three rounds so far, a 17th successive place in a Grand Slam quarter-final.

Haas was playing in his 53rd Grand Slam, just four behind the record of 57 for active players held by Roger Federer and Lleyton Hewitt.

The shock defeats suffered by Federer and Nadal in the first week had helped throw the tournament wide open with only five of the men's top 10 seeds, Djokovic, Murray, Ferrer, Tomas Berdych and Del Potro, reaching the fourth round.

Berdych, the seventh seed and 2010 runner-up, takes on unseeded Australian Bernard Tomic, a quarter-finalist in 2011.