Koe was trailing 3-2 before scoring three in the seventh end to advance to Saturday's quarter-final match against Edmonton's Kevin Martin.
Also moving on in a tiebreaker was Sweden's Niklas Edin, who downed Switzerland's Sven Michel 6-2 and will now play Glenn Howard of Coldwater, Ont., in the quarters. Howard finished first atop the round robin with a 4-0 record.
The other men's quarters featured Scotland's David Murdoch against Winnipeg's Jeff Stoughton, and China's Rui Lui against Denmark's Rasmus Stjerne.
In the women's tiebreakers, Scotland's Eve Muirhead battered Coldwater's Sherry Middaugh 7-1 in six ends, while Winnipeg's Chelsea Carey scored three in the fifth end to hold off Russia's Anna Sidorova 6-5.
Carey next plays another tiebreaker against Ottawa's Rachel Homan on Saturday. If Carey wins, she'll play Sweden's Margaretha Sigfridsson, who finished a perfect 4-0 atop the round robin.
If Homan wins, she'll face Heather Nedohin of Sherwood Park, Alta., while Muirhead will play Sigfridsson.
In the other women's quarters, Winnipeg's Jennifer Jones faces Saskatoon's Stefanie Lawton, and Mirjam Ott of Switzerland takes on South Korea's Ji-Sun Kim.