17 year-old William Bosi from Edinburgh has become the youngest Brit to climb 9a with an astonishingly quick redpoint of Rainshadow 9a at Malham Cove - his first of the grade. William's ascent is only the 6th ever after Steve McClure, Adam Ondra, Jordan Buys, Ben Moon and Stu Littlefair.

Malcolm Smith was aged 18 when he redpointed Hubble 8c+ - now considered 9a - in 1992.

Commenting on his Facebook page, William wrote:

"Super psyched and in shock after possibly my best ever day climbing. Where everything came together and I sent Rainshadow 9a!!! So happy and looking forward to what's next."

William required just a few sessions on the route, coming agonisingly close to ticking the climb on his tenth attempt. UKC happened to be present on the Catwalk when William was making good progress. When asked about his motivations for trying Rainshadow, William told us:

"Last summer I tried Bats and Dogs, which involves the top part of Rainshadow. The climbing on that is some of the best I've ever done, so I really wanted to do the whole thing."

On a chilly late afternoon attempt – feeling tired and with numb fingers – William fell just 5 moves from the chain. He commented at the time:

"My fingers turned painfully numb and I fell off on the last droppable move. I'm a bit gutted."

When asked if he was considering another attempt on the day, William replied:

"I haven't done enough of this outdoor redpointing to know how tired I'm feeling."

The longest period of time he'd ever spent working a route until now? He replied:

"About 2 days really. The hardest route I have ever done was out in Mallorca and took about two days of work. That was only 8c so this is a bit of a step up, over double the time I've ever spent on a route!"

When asked if this experience would inspire him to spend a little bit longer on something harder, William answered:

"I do enjoy doing stuff quite quickly to be honest, each time I made progress on the route I enjoyed it, but falling off on the same move over and over again wasn't much fun!"

Earlier this year, William made an impressive and equally rapid repeat of Monk Life 8B+ at Kyloe in the Woods. Now William has caught the bug for "this outdoor redpointing" malarkey, it looks like we might be reporting on some impressive ascents in the near future…

William is sponsored by: Wild Country and Red Chili.