Verdasco became the first left hander, other than world number one Rafa Nadal, to beat Murray in a grand slam and also notched his first victory in six matches against the Briton.

The 21-year-old Scot, one of the pre-tournament favourites and widely tipped to end Britain's 73-year wait for a men's singles grand slam champion, produced flashes of brilliantly controlled tennis but also made numerous elementary errors.

On several occasions throughout the match he chastised himself, at one point in the fourth set screaming "what the hell are you doing?".

The match was a see-saw affair with both men thrashing the other in the opening two sets before Murray seemed to have gathered momentum in the third when he took it 6-1.

The Hisense Arena crowd, the majority of whom seemed to be supporting Murray, then broke into renditions of the Scottish national anthem "Flower of Scotland" and chants of "if you love Andy Murray stamp your feet".

Murray, however, failed to capitalise and Verdasco broke in the second game of the fourth set and held on to the advantage to stretch the match into a decider.

The pair held serve until the sixth game of the fifth set when Verdasco saved two break points and produced several big serves to hold.

The Spaniard, who let out a loud yawp of excitement at the end of that game, broke Murray in the next game to give himself a 4-3 lead and when he held serve in the eighth as he sensed an upset was on the cards.

Murray held serve to narrow the gap to 5-4 but Verdasco produced three huge serves to give himself three match points.

Murray managed to save the first two in nerve-racking baseline duels but Verdasco sealed victory after three hours, 12 minutes when Murray's backhand service return cannoned into the net.

The 25-year-old Verdasco will next meet either fifth seed Jo Wilfried-Tsonga or James Blake, who play later.

Nadal safely through to quarter-finals

World number one Rafa Nadal breezed into the quarter-finals of the Australian Open on Monday with a 6-3 6-2 6-4 win over 2007 finalist Fernando Gonzalez.

The Spaniard raced to victory in less than two hours and is the only man to reach the last eight at Melbourne Park without dropping a set.

"I am playing well... but you never know if it's gonna be enough," said Nadal, who will face French sixth seed Gilles Simon next.

"I hope I continue playing like this, because all the (remaining) matches are very, very difficult. I have to be ready for everything."

Gonzalez had staged a remarkable recovery in his previous match against Richard Gasquet to reach the fourth-round, saving a match point and coming from two sets down to win, but the effort had taken an enormous toll.

The 28-year-old Chilean began slowly, dropping his opening service game, and the first set was over in 37 minutes.

Nadal raced through the second but found himself down 3-0 in third. The top seed recovered to reel off five games in a row before serving out victory.

"I think he was playing good. I just tried to go for my shots. I missed a couple in the beginning but Rafa, when he's up in the score, he's a different player," Gonzalez said.

"Of course, I was tired but I don't think it's the reason.

"I was able to run. I was able to compete today. Maybe I didn't play my best tennis."