Tom Dryden, from Earls Barton in Northamptonshire, described the news as "absolutely outstanding".
Lorna Clarke, from Oxford, took the the women's title. It's the second time she has entered the games.
Organisers said 190 competitors from countries including Russia, the USA and Japan took part in the event in Southwick, Northamptonshire.
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Since it began in 1965, the event has raised about Â£400,000 for blind and visually impaired charities.
Ms Clarke, a digital marketing manager said: "Its amazing.  The trick was skill, accuracy and a little bit of luck.  My colleagues will laugh but will be very impressed."
Mr Dryden, who is a Cub Scout assistant, said: "I never thought I'd win the first time I entered.  The cubs will be over the moon."
A new conker is used for every round. StJohn Burkett said preparations had been tough this year because of a shortage of decent conkers.
He said: "We collect a couple of thousand and we have to get the proper Championship-sized conkers. They're quite rare.
"We usually rely on two secret trees but even they haven't produced this year so we've had the whole committee out collecting."

The 28-year-old Croatia international will sign the deal, which has a £109m (125m euros) buyout clause, on Friday.
Rakitic - whose current contract runs until 2019 - has made 145 appearances for Barca since his 2014 move from Sevilla, scoring 23 goals.
He played in Barca's famous 6-1 comeback win against Paris St-Germain in the Champions League on Wednesday.

Margaret Aspinall and Trevor Hicks campaigned for more than 20 years to secure fresh inquests into the deaths of 96 people in the disaster.
Mr Hicks' daughters Sarah, 19, and Victoria, 15, and Mrs Aspinall's son James, 18, were among those who died at the FA Cup semi-final in April 1989.
Mrs Aspinall, chair of the Hillsborough Family Support Group, said she would accept it on behalf of the families.
A jury is currently hearing the new inquests in Warrington before coroner Lord Justice Goldring.
Mrs Aspinall said: "It's not just about Trevor Hicks and Margaret Aspinall, it's about everybody involved in this. It's all about the people who stood by us.
"From the beginning, when you are fighting against everything, nearly 26 years ago, you had this stigma against you all the time, fighting against that, I feel we have turned it all around now and the stigma is going away.
"People are seeing now, the real people, what the genuine people are like, and the people who stood by the families and stayed with them all these years, so it's for them as well."
Mr Hicks, president of the Hillsborough Family Support Group, said: "On a personal level, obviously I'm very flattered. I know it's a bit cheesy but I'm also a bit humbled as well.
"It's not just for me. As it says in the citation, it's for services to the bereaved families.
"It's been a hard slog. We've been accused many times of being vindictive - and lots worse than that. But we've always tried, as a family support group, to play fair."
Fellow campaigner Anne Williams, who died in April 2013, was honoured with the Helen Rollason Award at the BBC Sports Personality of the Year Ceremony in 2013.
Ms Williams, 60, fought for a new inquest into her son Kevin's death.
Two investigations are being carried out into the aftermath of the disaster - one led by police and one headed by the Independent Police Complaints Commission.
Other Merseyside & Cheshire honours include:
CBE
OBE
MBE
A new king has been crowned World Conker Champion after taking part in the annual games for the first time.
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Barcelona midfielder Ivan Rakitic has agreed a new contract, tying him to the Spanish champions until 2021.
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Two Hillsborough campaigners have been appointed CBE in the New Year Honours.