ST. CATHARINES, Ont. — It took an extra end, but Rachel Homan's team was the first into the playoffs at the Canadian women's curling championship.

The Ottawa Curling Club foursome edged provincial rival Krista McCarville of Northern Ontario 7-6 to get to nine wins without a loss Wednesday.

Just three teams have gone undefeated in the preliminary round since the national women's curling championship became the Tournament of Hearts in 1982: Homan (2014), Jennifer Jones (2013), Linda Moore (1985).

"It's more like scary because you're bound to lose a game," Homan said. "It's sport. It's really tough to go undefeated.

"You keep playing as well as you can. No matter what our record is at the end, we just need to win out in playoffs and that's our goal."

The defending champion gaining automatic entry into the following year's Hearts wasn't introduced until 1986, so Moore was 10-0 in 1985 while Homan and Jones went 11-0.

Ontario concludes their round robin Thursday against Quebec's Eve Belisle (6-3) in the morning followed by a much-anticipated showdown with Manitoba's Michelle Englot (8-1) at night.

"It's going to get awfully loud in here," Englot said. "I think we've picked up a few fans along the way."

The top four teams after the preliminary round's final draw Friday morning advance to the Page playoff. Ties for fourth get solved by tiebreaker games. The final is Sunday.

At eight wins, Englot was assured at least a tiebreaker.

Defending champion Chelsea Carey won her seventh straight to get to 7-1. Her Calgary team downed Stacie Curtis of Newfoundland and Labrador 11-5 in an evening draw.

Northern Ontario was chasing at 5-3. McCarville recovered from the loss to Homan beating Prince Edward Island's Robyn MacPhee 7-6 in an extra end.

The ice at the Meridian Centre became frostier and heavier over the course of the day because of warm, humid temperatures outside, and because a sensor on the dehumidification system had failed, according to ice technician Dave Merklinger.

The sensor was replaced, he said, but it would take overnight for the repair to take effect.

"It's the first time I've taken my jacket off in two days, so that's an indication right there it's really, really warm and really, really frosty," Carey said.

"Hopefully we get it a little cooled off for tomorrow because it was really nice and cool and the speed was beautiful the last three days."

With Heather Nedohin continuing to fill in for Shannon Kleibrink at skip, Alberta was tied at 4-4 with Kerry Galusha of Northwest Territories. Kleibrink hasn't played since Monday due to a sore back.

Alberta was up 9-5 at the fifth-end break, but let Nova Scotia's Mary Mattatall steal five en route to an 11-10 win.

"I think you can see by the stats I played terrible and I take full responsibility for that game," Nedohin said.

Four losses is often the cutoff for playoffs. Galusha stayed in contention for a possible tiebreaker with a 7-6 extra-end win over Saskatchewan's Penny Barker.

P.E.I.'s MacPhee, Newfoundland's Curtis and Nova Scotia's Mattatall were 2-6 ahead of B.C.'s Marla Mallett at 1-8. Barker was winless in eight.

Homan, third Emma Miskew and lead Lisa Weagle are two-time Canadian champions (2013, 2014). Joanne Courtney joined the team at second following the departure of Alison Kreviazuk in 2014.

They're the heavy favourite in this year's Scotties Tournament of Hearts. An extra-end win over Carey to open the tournament and Wednesday game that went to an 11th end have been Homan's toughest tests so far.

Ontario lost a measurement on Homan's draw for the win in the 10th against McCarville. But Homan was not short again in the 11th drawing in for the victory.

Englot is an experienced skip having represented Saskatchewan seven times between 1988 and 2012 and finishing third twice.

Her Manitoban squad meets B.C. on Thursday morning before what could turn into a game for first place against Ontario.

"Maybe it just seems like a fairy tale yet that I'm not feeling the pressure too much, but we have been playing fairly solid all year," Englot said.

"We know we need to beat B.C. and then it would come down to being a first-place battle against Ontario and that's exactly where we want to be."