The British cyclist Chris Froome has lost the race leader's yellow jersey despite surviving a day on the cobbles at the Tour de France.
The British rider was expected to be tested on the seven cobbled sectors that peppered the course, as the Tour crossed the Belgian border into France for the first time since the start in the Netherlands, but he passed with flying colours, despite being nearly brought down when he came into contact with an Italian rider.
German's 2013 champion Tony Martin won the 223 kilometre fourth stage with a late attack to take the overall lead.
Martin leads Froome by 12 seconds overall with the American Tejay van Garderen in third place at 25 seconds.
Among the other title contenders, Spain's Alberto Contador is eighth, 48 seconds behind Martin, and Colombian Nairo Quintana is 13th, one minute 50 seconds off the pace.