Terry, Lance and Gerwyn all grew up together in the same village and have been friends with Mike since meeting at their local rugby club over 20 years ago.
The friends are now planning a dream trip to New Zealand to watch the Rugby World Cup as well as the upcoming warm-up games which kick off when Wales face the Barbarians on Saturday 4 June (2.30pm).
"I'm thrilled that such passionate Welsh rugby supporters will share the Lotto winnings and hope that they can all make it to support the Wales team throughout the warm-up fixtures at the Millennium Stadium and on to the Rugby World Cup in New Zealand," said Williams.
Terry, who has managed the syndicate since they formed in 2003, said: "I normally check the tickets when I get up on Sunday morning. I was up at 7am so I checked Teletext to see if we'd won anything. The most we'd ever won was £80 a few years back so when I saw we had matched six numbers, I didn't believe it. I dragged my wife out of bed so she could check the ticket for me!
"I knew Gerwyn would be the only other member of the syndicate up at that time in the morning so I called him up to tell him but he didn't believe me so I had to go round to his house and show him the ticket. We then went round to Mike's house and banged on the door till he got up to tell him the news and then did the same to Lance. Once everyone knew, we went back to mine for a party!"