Poor conditions and an approaching bad weather front made a completely free ascent impossible.
David was leading most of the pitches in what he described as "really tough climbing" via sat phone.
"The day before I didn't feel well so I thought we had no chance of summiting. But when we got up the next day everything worked out perfectly."
At the top, photographer Corey Rich was also showing the first signs of altitude sickness. After the ten-hour climb they abseiled and arrived at the bivi on the sun terrace late at night from where they descended to basecamp the following day.
David Lama and Peter Ortner are now staying in Pakistan to climb Chogolisa (7668m) as a training run to find out how they perform at high altitude.
David Lama has several sponsors including Mammutand Red Bull