Skip Ji-Sun Kim made a tap for two points and a 4-3 win in Saturday's game between the third and fourth playoff seeds.
The South Koreans lost 9-6 to Switzerland in the later semifinal and will play the Canadians again for bronze Sunday.
Nedohin, who threw third stones for Cathy King in her last world championship appearance 14 years ago, will play for the lesser medal yet again.
"There's no way we're losing that bronze game," Nedohin said as her voice shook and the tears came. "I did the damn same thing in 1998. I'm going to win the bronze."
Switzerland's Mirjam Ott is a two-time Olympic silver medallist, but she'll play in her first world championship final Sunday against Sweden's Margaretha Sigfriddson.
A Swiss team hasn't won a gold medal since 1983 when Erika Mueller's foursome was victorious in Moose Jaw, Sask. Ott's one medal at the world championship was a bronze in Vernon, B.C., in 2008.
"Playing a final in Canada at the worlds is just awesome," Ott said. "We like playing in Canada better than anywhere in the world."
Canada last won gold in 2008 in Vernon where the Jennifer Jones team prevailed. Kelly Scott in 2007 and Colleen Jones in 2004 were the other two victorious Canadian teams in the last decade.
Kim team from Euijeongbu City is the surprise of this tournament. The country has appeared in just four women's world championships since 2005.
Kim went 2-9 skipping South Korea last year in Denmark, but the country has begun intensively preparing its athletes to excel in the 2018 Winter Olympics in Pyeongchang.
Saturday's playoff game was the first at the women's world championship for South Korea. Kim had a clear strategy of a conservative, hitting game to keep the score low and close.
"It was on purpose that the strategies were very simple," Kim said through an interpreter. "In order to be able to beat Canada, the way would be not to make too big of a score difference."
With last-rock advantage to start the game, they blanked the first two ends, the fifth when they got the hammer back and again in the ninth to be down a point coming home with hammer.
"I thought the Koreans came out not to play against us," Nedohin said. "They were extremely defensive from the get-go. The only entertaining end was the last one and she did make a pistol. It was a great shot to win.
"I was ready to play the game. Maybe that's a good tactic against us, to play extremely boring. Congratulations to them. They got a 'W' out of it. I just don't think it was an entertaining game whatsoever."
Boring or not, Canada was unable to draw the South Koreans into much trouble with the exception of the sixth end when the hosts stole a point.
The Canadians didn't play badly, shooting 87 per cent as a team, but their shooters rolled out of the rings on hits at times to take the pressure off the opposition.
"We had a couple of opportunities where we could have pressed the issue a little bit," third Beth Iskiw said. "Not that we played poorly, but we could have made it a little bit harder for them."
When there were rocks in play in the 10th, South Korean third Seul-Bee Lee executed a couple of key hit and rolls to position rocks advantageously.
Iskiw missed a runback double and a subsequent corner-freeze attempt bounced out in the open. Nedohin also wasn't precise enough with her corner freezes.
Kim's hand was visibly shaking on her penultimate throw of the end, but she still made a double hit to lie two. Nedohin's attempted corner freeze on her final throw was just short of being shot rock, leaving Kim a raise on the top of the four-foot rings for two points and the victory.
"I thought I would win," the petite skip said. "I thought it in my mind before the game started that I would win and that's why I was able to not be too scared or afraid of this game."
A small, but vocal band of supporters for South Korea engaged in a cheer battle with the pro-Canada Enmax Centre, which made for a lively atmosphere.
Canadian women have finished out of the medals just five times in the 33-year history of the tournament. Nedohin, Iskiw and front end Jessica Mair and Laine Peters need to emotionally recover from their loss in order to not be the sixth.
"I think it's devastating," Peters said. "I'm not happy at all. We came here to win gold. We're not going to do that now.
"We have to now regroup and come out and win bronze. We will do that. It's certainly our new goal. I don't think we're quite there yet, but we will get there."