Stage 12, the Bastille Day stage, was the first particularly difficult mountain stage in this Tour. It ended at the hors catégorie climb Luz Ardiden, and also visited the hors catégorie Col du Tourmalet and a never-before-seen first category climb La Hourquette d'Ancizan. Sánchez effectively stayed with the group of overall favorites throughout the day, and attacked with Omega Pharma-Lotto's Jelle Vanendert on the way up to Luz Ardiden, surpassing the morning breakaway. Starting his sprint for the finish line from out, Sánchez won so convincingly that he opened up a 7-second time gap on Vanendert. It was Sánchez' first Tour stage win of his career and just the third in the team's history - one of them had come from former rider Roberto Laiseka on this very mountain in the 2001 Tour de France. Given the new points system for the mountains classification, Sánchez took the polka-dot jersey as mountains leader due to this win, even though he had not previously scored a single point. The result also installed him into the top ten overall for the first time, as he occupied eighth place. The next day, by winning the Col d'Aubisque climb, Jérémy Roy took the mountains classification lead from Sánchez. In stage 14, the overall favorites chased down a breakaway on the way to the Plateau de Beille summit finish. Once they occupied first position on the road, Andy Schleck tried numerous times to escape but was unable. Vanendert went, and no one but Sánchez put in any serious attempt to chase him down. Vanendert won the stage, and took the mountains classification lead, with Sánchez finishing second, exactly reversing their fates from stage 12. Sánchez also improved to sixth overall with this result. Sánchez improved further in stage 16. While previous race leader Thor Hushovd won the stage from a breakaway, Sánchez, as well as Cadel Evans and Alberto Contador, took time out of some of the race's other top riders by riding away from them on the descent to the finish. Evans was three seconds the better of Sánchez and Contador, who were in turn 18 seconds faster than race leader Thomas Voeckler, Fränk Schleck, Damiano Cunego, and others. They were also 51 seconds the better of Ivan Basso and more than a minute better than Andy Schleck. This result moved Sánchez up to fifth place. Sánchez lost time on stage 18 on the Col du Galibier, finishing 18th almost five minutes behind stage winner Andy Schleck and between one and three minutes behind the race's other top riders. He fell back to eighth because of this.