Koe improved to a 2-1 record in the tournament while Jacobs's rink from Sault Ste. Marie, Ont., fell to 0-2.
Also in Draw 9, Glenn Howard (2-1) beat Jeff Stoughton in seven ends in a 7-3 win. Howard, from Penetanguishene, Ont., bounced back from a 5-2 defeat to Brad Gushue of St. John's, N.L., earlier Thursday. Stoughton, from Winnipeg, dropped to a 1-2 record.
Winnipeg's Mike McEwen (3-0) topped Switzerland's Peter de Cruz 6-3 in seven ends.
Sweden's Niklas Edin (2-1) scored one in the final end to slip past Jim Cotter (0-3), from Kelowna/Vernon, B.C., with a 6-5 victory.
In the women's division, Sweden's Margaretha Sigfridsson (2-1) earned a 7-3 win over Scotland's Eve Muirhead (0-3).
In Draw 8 action, Winnipeg's Jennifer Jones improved to a 2-1 record with a 7-3 win in seven ends over Edmonton's Val Sweeting (2-1).
Switzerland's Binia Feltscher (3-0) scored two in the final end for a 6-5 win over Winnipeg's Kristy McDonald (1-2). Switzerland's Alina Paetz (1-2) dispatched Edmonton's Chelsea Carey (1-1) in an 8-3 win.
Switzerland's Silvana Tirinzoni (2-1) rallied from a four-point deficit to defeat Ottawa's Rachel Homan 8-5.
On the men's side, John Epping had a triple in the sixth end as the Toronto rink dumped Norway's Thomas Ulsrud (0-3) by a score of 5-4.
In the seventh draw, McEwen scored two points in the final end for a 4-3 win over Switzerland's Sven Michel (2-1).
Saskatoon's Steve Laycock (3-0) used a deuce in the final end to get past Cotter 6-5.
Scotland's David Murdoch (1-2) earned his first win of the tournament with a 7-6 victory over Calgary's John Morris (1-1).
Edin scored a triple in the fourth and stole two in the fifth during a 7-3 win in six ends over Koe.
In Draw 6, Homan earned a 7-4 victory over Sherry Middaugh, from Coldwater, Ont. Middaugh now holds a 1-2 record at the tournament.
Sweeting recorded a 7-4 win over Russia's Anna Sidorova (1-1).
Saskatoon's Sherry Anderson (1-1) scored one in the extra end to edge Sigfridsson for the 6-5 win.
Edmonton's Heather Nedohin (1-2) earned a point in the final end to lift her rink to a 3-2 win over Allison Flaxey (1-2), of Listowel, Ont.