ALBI. Green jersey holder Peter Sagan extended his lead in the Tour de France points competition as he out-sprinted John Degenkolb to win stage seven.Britain’s Mark Cavendish saw his chances of winning the green jersey suffer a blow as he was part of a group dropped on the second climb of the day.Slovak Sagan, last year’s green jersey winner, won by a bike length in Abli to take his first stage of the 2013 Tour. Chris Froome finished in the peloton as Daryl Impey retained the yellow jersey. With no real change in the overall race standings, Friday’s 205.5km race from Montpellier was all about the points jersey and Sagan tightening his grip on the green top.Sagan picked up 45 points for the stage win, to add to the maximum 20 he collected for winning the intermediate sprint to move onto 224 points, a 94-point lead over Germany’s Andre Greipel, while Cavendish is third on 119.