On Wednesday, June 3, 2015, Swiss climber Cedric Lachat and Frenchman Fabien Dugit managed to succeed on the first free ascent of Ballade au Clair de Lune (8b) (380m maximum difficulties of 8b) on the South Face of the Aiguille du Fou.

The route - originally an A4 aid climb by Jean Marc Boivin, Eric Bellin, and Martial Moioli from the early 80s - tackles the wall right of the famous American Route on the stunning granite South Face of the Aiguille du Fou, Mont Blanc Massif.

Lachat and Dugit have graded their free ascent 8b and said that although they aided the hard pitches before they managed to free the route (which is difficult in its own right) they didn't have time to fully rehearse the free climbing on a top rope before they went for 'the send'. Cedric explained on the Petzl website:

"To send the difficult and dangerous pitches, our original plan was to top rope them first to make sure we were solid. The reality of our situation was that we just didn't have the time, so we made the choice to simply climb and not fall.

When we reached the legendary A3-A4 pitch, rated 8b, I still took the time ascend the fixed line and preview the climbing, marking a few key holds here and there. Next, I started climbing for the send, without working the pitch beforehand. Honestly, a fall was simply not allowed: one, to avoid pulling any gear (there are two old aid bolts on the slab, and I would bet my left leg that both will pull if anyone ever falls on them, and yes I almost soiled myself), and two, we just didn't have the time for a second attempt. So I just went for it and sent, and Fab the machine seconded the pitch without falling."

The face, whilst not the biggest in the Alps, has relatively difficult access, with a rockfall exposed snow couloir blocking the entrance to the face. The pair's first attempt on the route saw them turn back before they had a chance to set foot on the rock face. Fabien commented on the Petzl Website:

"We started from the Aiguille du Midi with huge packs (static ropes/pitons/cams/…). After a night in the Réquin hut, we embarked on the approach to the Fou, but snow conditions were horrible, and our packs way too heavy.

After breaking trail in knee-deep snow, and making trips back and forth in the approach couloir to shuttle gear, we were completely exhausted once we were finally standing at the base of the route. Without a portaledge and no place to bivy, we decided to ski back down to Chamonix that very day. Cédric was still super motivated to attempt the face, which he had never seen beforehand."

Another couple of attempts and the pair had cracked it, but not without some exciting leads. Cedric commented:

"Fab and I would just tell each other, "don't fall", before each lead

Even with bomber protection, we still couldn't place much on each pitch. While we made sure that each pitch was protected, the route is still in the high mountains, so pieces were sometimes 10 to 20 meters apart, and more than a few flakes were just asking to be trundled. The mountains require a certain level of understanding and an ability to read the terrain. For that, I think that we both have plenty of experience."

• For more photos and an interview with Cedric and Fabien see the Petzl Website.

Cedric Lachat has several sponsors including Petzl and Scarpa