The 21-year-old from Bridgend saw off the challenge of Iranian discus rival Mehrdad Karam Zadeh at the Olympic Stadium with a best throw of 46.14 metres, setting a new European record in the process.
"Four years of hard work have gone into this. It's nice to give something back to everyone. I'm just so happy I performed," Davies said.
"I learned a lot from the shot put. It wasn't going to be easy as there were a lot of incredible athletes out there."
Davies was born with talipese and hemi-hemilia of the right leg - a combined disability which limits how his leg works and means missing bones, and no muscle growth or ligaments.
As a youngster he competed for Bridgend Surf Life Saving Club before he made his switch to athletics.
Davies soon proved his throwing talent by taking shot put gold and discus gold at the 2010 World Junior Championships, improving on the previous year's discus silver and fourth place in the shot.
He won gold and silver in the shot and discus at the 2011 World Athletic Championships in New Zealand, and also overcame a serious knee injury to win his Great Britain place at London 2012.
The Welshman's impressive build-up to the Paralympics continued in April when Davies broke the F42 shot put world record with a throw of 14.56m at the CP Grand Prix in Gateshead.
Davies, who delayed going to university to boost his Paralympic chances, said: "I can't put it into words. I've worked so hard - you don't realise; four years, I've had to defer uni.
"I did two years without funding, with a part-time job, got funding in 2011, managed to work my butt off and then managed to be able to perform."
After his Paralympic medal double at London 2012, one of Davies' major targets is winning medals for Wales in his category at the 2014 Commonwealth Games in Glasgow, while he has also speculated on the possibility of competing against able-bodied opponents at future events.
Voting lines for BBC Cymru Wales Sports Personality of the Year 2012 will open from 08:00 GMT on 3 December and close at 18:00 GMT on Saturday, 8 December.
Full voting terms and conditions will be available on the BBC website and will also be carried on radio and television.
The winner will be unveiled on the evening of Monday, 10 December and there is an awards ceremony that evening at the Millennium Stadium in Cardiff.
This event is not connected with the UK Sports Personality of the Year and is for the Wales award only.