Andy Schleck left three-time champion Alberto Contador floundering in the thin mountain air as he outwitted, outpaced and outclassed his Tour de France rivals with an inspired climb to win the 18th stage on Thursday. The Luxembourg climber, runner-up to Contador in 2009 and 2010, reached the top of the 2,645-meters Galibier pass – the highest ever finish to a Tour stage – on his own but his efforts were not enough to dislodge Thomas Voeckler from the yellow jersey. Contador's hopes of a fourth Tour triumph suffered a huge blow as he could only trail in 15th – 3:50 behind Schleck to remain seventh overall and needing to produce something special in the closing stages if he wants to celebrate in Paris again on Sunday. Frenchman Voeckler, his face distorted by pain and suffering, crossed the line 2:20 adrift to retain his lead which now stands at just 15 seconds over the stage winner. The other strong man in this gruelling 200.5-km ride into headwinds from the Italian town of Pinerolo was Australian Cadel Evans, who led the chase behind Schleck in the final ascent almost on his own, with Voeckler on his heels. Third over the line behind Andy's brother Frank, the 2009 world champion lies fourth overall, 1:12 behind Voeckler, an ideal position for Evans given his time trial skills. The Tour unfolds in the next two days with a compact but scary ride to l'Alpe d'Huez Friday, followed by a hilly individual time trial in Grenoble. Leopard Trek team leader Andy Schleck stunned the rest of the field by attacking early in the second classic climb of the day.