Walsh smashed his own national record, set new area record and a new World lead with the biggest throw in the sport since 2003.
His record effort easily surpassed his previous best of 22.31 metres, and the 22.67 mark sees Walsh now tied for ninth on the all-time list.
"It felt pretty easy and felt pretty good – I got through it pretty well. I knew it was far I just didn't know it was quite that far – it was great to just put that one throw together."
The world record has stood for 28 years, with Randy Barnes - who was later banned for life due to doping - hurling 23.12 metres in 1990.