Robert Pope from Liverpool believes he has achieved a feat that nobody before him ever has; running across Ireland in less than 24-hours.
Pope ran from Galway to Dublin in 23 hours and 39 minutes.
The 44-year-old got his 211km journey underway after having a pint of Guinness before enjoying another one after successfully completing his challenge.
Pope decided to take on the ambitious challenge less than two months ago and then decided he would use it to fundraise for the World Wildlife Federation.
Robert Pope driven by fear of failure
The ultra runner's training was hampered after he decided to go to Glastonbury but he turned his fear of failure into a massive motivator.
"Ultrarunning has exploded in the last few years, and a lot of that is because on social you'll often see people doing these crazy bonkers runs," Pope told the BBC.
"But nobody ever posts anything about failure anywhere. You see a lot of people posting and if they have failed at something they're like 'I'm absolutely gutted because I didn't succeed', but they did succeed because they gave everything they had to get there."
Pope got his challenge underway from the Spanish Arch on Saturday night but it wasn't long before he began to fatigue.
"The wheels nearly came off very early, because we'd gone about 24 miles, maybe 4 hours into it, and I'd been nauseous for the last two.
"I just said to the guys, I don't think this is me over-reacting, but I think I'm going to have to quit."
He made a quick recovery after refuelling with a can of coke and some painkillers.
Pope had a support team of four but was helped along the way by people who had heard of his efforts on social media.
In Cloghan, Co. Offaly, the staff of a local shop provided him with cereal bars to help boost his energy levels, while a runner named Tony helped him get through the final stretch of the run into Dublin.
"I had about 10 miles to go," says Pope.
I'm in a hole at this point and Tony comes along and asks, 'Do you mind if I run with you' and I was just like 'yeah, but I really need to concentrate now.'
"So, we just worked together, and it got to the point where I was following him... he would warn oncoming traffic. We came off the Royal Canal heading down into Dublin as the sun was going down."
Pope aimed to have a pint in Dublin before the end of the 24-hours and did exactly that.
He is no stranger to pushing himself to the boundaries of human endurance having previously nearly ran 25,000km across America over 422 days.
15,000 miles. 2500 x height of #Everest, a 15th of the way to the #moon, 4 x as long as the #Amazon and #GreatWall of China, 5.5 x the distance from #LA to #NYC...or...this run, consisting of 400 days of rubber on tarmac. 37.5 miles a day.#goingthedistance.@wwf_uk @peacedirect pic.twitter.com/khWA5bwwQv
— Robert Pope (@runroblarun) March 6, 2018
While he thinks he is the first person ever to pull off his achievement last weekend, he isn't 100% sure noting that "some gnarled old club runner from Cork could have done it once in January".