It looked like 2015 Winter Games champions Charley Thomas and Kaylynn Park might steal a win in the final stages after trailing for most of the match, but the young Estonia team of Marie Turmann and Harri Lill held their nerve for a 7-6 win.
Leading 6-5, Park had a chance to win or, more likely, force the Estonians to take the match into an extra end with her last stone of the match but missed a double take-out leaving Turmann an easy shot to take two points and the win.
''They really bought their game in the end and, of course, we were nervous but we were able to keep our nerve for the win,''Lill said.
Turmann put the win down to the teamwork between her and Lill.
''Our teamwork won it because we swept every stone like we meant it.''
The young Estonian pair leapt out to a four-point lead early as the Canadians struggled to find the right lines in the first four ends.
Coming out of the fourth-end break, the Canadians needed to start to claw back the Estonian lead if they wanted any chance of making a comeback.
The turning point of the match came in the second-last end after Canada was able to steal three points despite being disadvantaged by not having the last throw.
Turmann tried to limit the damage with a hard take-out shot but could not dislodge the three Canadian stones closest to the centre.
Despite being let back into the match the Canadians were unable to take advantage and go back to back.
''We had a chance there in the eighth with our last stone but I missed and that was that, '' Park said.
They will now return to the northern hemisphere to prepare for the Canadian Olympic trials in January.
''That's one of the reasons we wanted to come down here because the timing of the tournament is ideal for us leading into our season,'' Thomas.
In the third-fourth playoff match, Norway's Kristin Skaslien and Magnus Nedregotten came out on top over South Koreans Kijeong Lee and Jang Hyeji 9-2.
Six of the countries which competed at the tournament have qualified for the Winter Olympics in South Korea.
The South Korean, Swiss and Finish teams will compete at the Winter Olympic while the Canadians, Norwegians and Japanese will have to travel home to compete in their country's Olympic trials.
It is the first time mixed doubles curling has been included in the Winter Olympics. Fours has been an Olympic discipline since 1998.
