Pre-race favourite Tony Martin seized the lead in the Paris-Nice cycling race when he won the sixth-stage individual time trial over 27kms on Friday.

The 25-year-old German covered the difficult and varied course in 33 minutes 24 seconds, beating Briton Bradley Wiggins by 20 seconds and another time trial specialist, Australian Richie Porte, by 29.

Martin's fellow German Andreas Kloeden, who took the yellow jersey after his victory in the previous stage, fought bravely but had to settle for fourth place, 46 seconds adrift.

He lost the overall lead to Martin by 36 seconds. Wiggins lies third, a further three seconds adrift.

Ireland's Nicolas Roche was 50th in the time trial, finishing 3'07 behind Martin. He is now in 40th place, 5'58 behind the leader.

'My first goal was to win the stage, it's always nice to win a stage on Paris-Nice, especially a time trial. It was tough but now I have the jersey, it was the real goal and I hope to defend it in the next few days,' said Martin, the discipline's world bronze medallist.

Two tough stages are scheduled for the weekend, starting with a 212.5-km bumpy ride to Biot-Sophia Antipolis on Saturday.

'I have a very strong team so I really hope I can take the jersey to Nice and I'm confident I can do it,' added Martin, who leads the powerful HTC-Highroad outfit .

With Kloeden on his heels, American Levi Leipheimer in sixth spot, 1:29 behind, and Slovenia's Janez Brajkovic seventh, 1:32 off the pace, Martin said he feared team RadioShack more than any other rivals.

'It's so close in the (standings) that every rider in the top 10 is dangerous, especially the RadioShack guys. They have two riders who can make a good race and attack. One can go and the other can watch me,' he said.

Martin said he was pleased to put Germany back on the cycling map after doping scandals shattered the sport's image in his native country.

'I hope the Germans see this and maybe come back to watching cycling and start to like it again like when (former Olympic champion and Tour de France winner) Jan Ullrich was so popular. I hope this will help cycling come back to Germany.'