"The Coke was a bad idea. I got the stitch about halfway up."
Despite the stomach ache, the 11-year-old managed to make it up Baldwin St in about 10 minutes — without stopping.
And in the process, he raised more than $7700 for Ronald McDonald House in Christchurch.
Harry said the organisation was close to his heart because it provided his family with support and "a home away from home" when his sister, Darcie, was receiving cancer treatment in Christchurch last year.
Having the family stay together and visit Darcie in hospital regularly, played a major part in her recovery.
Before Harry started the challenge, he was only 75% confident he would make it to the top because he had been doing flips on a trampoline a few days earlier and hurt his back.
"I was worried this morning because my back was hurting.
"I started getting tired about halfway through.
"Nearer the top, I didn’t think I was going to make it. I thought I was going to trip.
"But the crowd pushed me to go over my limits. They were great. I didn’t expect there to be so many people here."
He had a steely look of determination as he made his way up the street and was followed by members of his family and a group of about 50 children shouting "Go Harry".
Many have tried to climb Baldwin St in weird and wonderful ways, including on stilts, rollerblades and a penny-farthing.
Harry now holds the unofficial record for being the first person to pogo-stick up the steepest street in the world.
He chose the pogo stick as his means of transport after playing with his brother’s one.
"I started pogo-sticking a couple of years ago when my brother got one for Christmas."
• Harry’s fundraising page is: https://give.everydayhero.com/nz/pogo-stick-up-baldwin-street-boy
