Koe's Calgary rink scored three in the first end and four in both the third and fifth ends.
Both Koe and Halifax's Dacey are at 1-1 in the tournament.
Defending champion Jeff Stoughton of Winnipeg is also 1-1 after a 6-3 win in six ends over Edmonton's Brendan Bottcher.
Stoughton scored steals of two in the second and one in the third to lead 4-0 after three ends and never looked back.
Winnipeg's Mike McEwen improved to 2-0 with a lopsided 10-3 win in five ends over Japan's Yusuke Morozmi. McEwen opened the game with a huge five-point first end.
Glenn Howard, from Coldwater, Ont., kept pace with McEwen with a 7-4, seven end win over Switzerland's Pascal Hess.
Elsewhere, Switzerland's Sven Michel improved to 2-0 with a 7-4 win over Toronto's Travis Fanset.
There are two more draws scheduled for Thursday.
The tournament is the third instalment of the Grand Slam of Curling with the series finale Players' Championship scheduled for next month in Summerside, P.E.I.