* Pyeongchang wins 2018 Winter Olympics by big margin
* Explosion of joy and relief in South Korea
* Munich and Annecy bow out in graceful defeat
By Paul Radford
DURBAN, July 6 (Reuters) - South Koreans reacted with unashamed joy and relief as the city of Pyeongchang overcame two past disappointments to win the right to stage the 2018 Winter Olympics in a surprisingly easy victory over their European rivals.
The Pyeongchang delegation at the International Olympic Committee session in Durban erupted in wild cheering and chanted "Korea, Korea" on Wednesday as IOC President Jacques Rogge announced their victory over Munich of Germany and Annecy of France.
In Pyeongchang itself, thousands of Koreans, including soldiers, robed monks and young children, waited up late at night at the base of the Alpensia ski jump to celebrate.
Elsewhere throughout the country there were gatherings at numerous venues where relieved Koreans reacted with tears, dancing and displays of fireworks.
The Korean city had bid twice before and gone agonisingly close to victory before losing to Vancouver of Canada for the 2010 Games and to Sochi of Russia for 2014.
This time there was no room for doubt. Pyeongchang won in a canter, taking 63 votes to 25 for Munich and seven for Annecy as they won by a crushing margin on the first round of voting.
Rogge expressed his surprise, saying the IOC had expected a second round of voting and a much closer margin of victory.
"This is one of the happiest days for our country, our people and millions of youth dreaming of winter sport," Pyeongchang bid chief Cho Yang-ho told Reuters seconds after the announcement. "We have been waiting a long time for this."
The country's president Lee Myung-bak, part of a bid team which also featured Olympic women's figure skating champion Kim Yuna, told Reuters: "It feels great."
The Koreans had strongly emphasised the fact that their country had never before staged a Winter Games, using the slogan "New Horizons", and reminded the IOC that the event had only twice before been staged in Asia, both times in Japan.
The Munich bid team, lead by former Olympic figure skating champion Katarina Witt and featuring former Bayern captain Franz Beckenbauer, issued a statement saying: "Of course we are disappointed because we came here to become the host of the 2018 Winter Games.
"But the IOC has decided to award this honour to another candidate and because we are a sporting team, we accept this decision. We always knew that this would be a very tough race alongside two strong competitors."
Annecy bid leader Charles Beigbeder told Reuters: "I am very disappointed. We were hoping to be selected but we congratulate Pyeongchang who were great competitors."
Both European bids had stressed their strong winter sports traditions but the IOC was plainly in the mood for taking the Games into a new territory.
This is a growing trend for major sports events with recent Summer Games going to Beijing and Rio de Janeiro, a first for China and for South America, and soccer World Cups being awarded to South Africa and Qatar, firsts also for Africa and the Middle East.
(Additional reporting by Karolos Grohmann, Jon Herskovitz and Jason Humphries in Durban and Jeremy Laurence in Pyeongchang)
(Editing by Justin Palmer; to query or comment on this story email email@example.com)