Bayliss was one of 24 golfers - all Mercedes-Benz owners - entered in the two-day tournament, run by ParNZ, at Millbrook Resort.
All players had qualified at one of nine tournaments held nationally.
Bayliss, a member of the Wanaka Golf Club, said it was ''absolutely'' the win of his life and he was ''gobsmacked''.
''It's bloody marvellous.
''I was only good because I had really good partners on the course with me ... who supported me the whole day.
''The last nine my partner was just saying to me `Calm down, Mike'.''
He will be joined by second place-getter Mark Jeffries, of Gulf Harbour Country Club on the North Shore, and third place-getter Peter Jordan, the overnight leader of the tournament on Saturday.
Jeffries said he had been playing golf only about 18 months but he was ''just so pleased to be here''.
Jordan, of Remuera Golf Club, in Auckland, said the cooler temperatures on Sunday affected his game.
''I did struggle with it and struggled to get the game together. It was an issue.
''I'm thrilled ... this is one of the highlights of my life, let me tell you.''
The trio will be flown to Stuttgart, Germany later this year to play in the 25th anniversary of the Mercedes Trophy World Final, against representatives from more than 60 countries, including China, Bulgaria, the United Kingdom, the Netherlands, Egypt, Lithuania, Turkey and Kuwait.
Mercedes-Benz New Zealand general manager Ben Giffin, of Auckland, said the New Zealanders would spend a week in Germany and enjoy an opening night similar to the Olympics.
''It's really something quite special to compete for your country at a tournament that's this large.
''All I can say to ''Team New Zealand'' [is] it's really about an experience - it's about friendships.''
Another winner on Sunday evening was Larry Olsen, of Lochiel Golf Club in Hamilton, who won the ''Drive to the Major'' by having the straightest drive at one hole.
Four players were close to the target, the two closest within 2m of the line.
Olsen, however, was 1.9m away, booking him a trip to Royal Liverpool - or Hoylake - for The Open Championship in July, playing the course the morning after the champion is crowned.
Olsen said it was a ''total surprise'' and it was ''wonderful''.
''I think the first thing ... is how to go back to Hamilton and tell all of our non-golfing friends I had four days in Queenstown, played one shot and got a free trip to England.''
Sunday night's prizegiving at the Millbrook Country Club capped off a fun-filled stay for the golfers and their partners, who arrived in Arrowtown on Thursday.
On Friday the group enjoyed an Anzac-inspired informal barbecue, before a German-themed event on Saturday evening, with special guest Sir Russell Coutts, before the formal dinner and prizegiving.
The group raised just over $1100 for the RSA through donations and a silent auction of a polo shirt signed by Australian professional golfer Adam Scott, which sold for $810.55.
