Wimbledon 2012: Novak Djokovic beats Radek Stepanek

Top seed Novak Djokovic avoided falling victim to a Centre Court upset as he fought back from a set down to beat Radek Stepanek 4-6 6-2 6-2 6-2.

On the stage where Rafael Nadal had come unstuck against Lukas Rosol, Czech Stepanek broke late to seize the first.

But Djokovic surged through seven straight games to carry off the second, build a solid lead in the third and break the back of Stepanek's challenge.

The defending champion will play fellow Serb Viktor Troicki next.

"It was a tough match but I think I played second third and fourth well," said Djokovic.

"I knew he was very experienced and he is one of the few who comes to the net and has a lot of variety and a lot of shots that can hurt anybody."

Rosol's victory over Nadal the previous evening had been the talk of the Championships on Friday morning, and imaginations were set racing on Centre Court as Djokovic put a heavy volley between the tramlines to concede a break in the final game of the opener.

The world number one had squandered five break points in the first set, but he recovered his ruthless edge to break in the opening game of the second set.

Stepanek had beaten Djokovic back in 2006, but his hopes of a repeat were left in tatters as the Serb tore away under a roof closed against intermittent rain.

The Czech's attempts to force Djokovic out of his stride by pressing the net proved in vain as his opponent threaded winners down either wing and over the top of him.

Stepanek summoned up the last of his reserves to hold serve in an attritional fifth game of the final set, but he could not hold back the tide for long.

Djokovic completed his victory in two hours and 50 minutes to suggest that, with Nadal already out, he is building ominous momentum towards the final.

His fourth-round opponent Troicki knocked out the 15th seed Juan Monaco of Argentina 7-5 7-5 6-3.

Several other seeds also fell on Friday. Belgium's Xavier Malisse beat Spanish 17th seed Fernando Verdasco 1-6 7-6 (7-5) 6-1 4-6 6-3 to also reach the fourth round while Serbia's Janko Tipsarevic was knocked out by Russia's Mikhail Youzhny, the 26th seed beating the eighth seed 6-3 6-4 3-6 6-3.

France's Richard Gasquet also defeated a higher-ranked player, the 18th seed despatching 12th seed Nicolas Almagro of Spain 6-3 6-4 6-4.

American Sam Querrey defeated Canada's 21st seed Milos Raonic 6-7 (3-7) 7-6 (9-7) 7-6 (10-8) 6-4 in a round two match.