In 2016 Jernej completed the 9a+ (5.15a) graded deep-water soloing route Es Pontàs in Mallorca. The route was originally established by Chris Sharma in 2006. Jernej was only the second climber to repeat it. It took him 16 days and 39 attempts to finish the route.[2] Jernej initially graded the route 9b (5.15b). Jan Hojer, who got the third ascend on the route, downgraded it to 9a+.[3][4]
In September 2018, he managed to get the first ascent on the boulder, Metafizika, near Celje, Slovenia. It has a bouldering grade of 8C (V15), and was only the second boulder of that difficulty in Slovenia.[5][6]
On 31 December 2018, Jernej made the first ascent of Dugi rat at the crag Vrulja close to Omiš in Croatia. With a grade of 9a+ (5.15a) it is the hardest sport climbing route in the country. Jernej bolted the route himself and had been working on it for 4 years. The name Dugi rat means "long cape/horn" in Croatian.[7]
