A 4-2 win Thursday night over Quebec's Jean-Michel Menard put the defending champions at 9-0.
Howard's round-robin wins over Manitoba's Jeff Stoughton and Brad Gushue of Newfoundland and Labrador, both 7-2, ensured Ontario would be ranked higher in the event of a tie with either rink.
"The bottom line is, I think we're No. 1 no matter what," Howard said. "That's the first goal, so we made it. With two games to go, that's fantastic."
The top four teams at the conclusion of the round robin Friday make the Page playoffs, with ties for fourth solved by tiebreaker games.
Eight wins has made the cut every year since playoffs were introduced into the Brier format in 1980.
Seven wins has been good enough some years, but not enough for teams with four losses to be confident of securing a top-four spot. A tiebreaker game is a more realistic hope for a team that sits at 7-4.
The top two teams in the preliminary round meet in a Page playoff Saturday, with the winners punching their ticket to Sunday evening's final.
The loser drops to Sunday morning's semifinal against the winner of Saturday's playoff between the third and fourth seeds. So Howard's reward for a top-two finish is a second chance in the playoffs.
He will make a bid to go undefeated through the preliminary round. His was the last team to do so when Ontario went 11-0 at the 2010 Brier in Halifax. Alberta's Kevin Martin also went unbeaten in the 2008 and 2009 Briers.
Howard's rink finishes the round robin versus Prince Edward Island and then, coincidentally, Martin in Friday's final draw.
"We're going to go and try and win our next two," the Ontario skip vowed.
After ruthlessly mowing through the field for most of the week, Howard had to sweat for a pair of wins Thursday.
Ontario held off a tenacious Newfoundland 6-5 before Quebec's Menard missed an in-off by mere centimetres for the win.
Northern Ontario's Brad Jacobs and Quebec were both 6-3 ahead of Martin at 5-4. Saskatchewan's Brock Virtue and New Brunswick's James Grattan were both 4-5.
Kevin Koe of the Territories (3-6) was eliminated from playoff contention Thursday as was the 1-8 teams of B.C.'s Andrew Bilesky, Nova Scotia's Paul Flemming and Prince Edward Island's Eddie MacKenzie.
Manitoba fell 9-4 to an inspired Northern Ontario team, but was still in position to claim a top-two seeding Friday. Stoughton has the Territories and B.C. as his final opponents Friday.
"It's good that we don't have to look around and watch anybody else," Stoughton said. "We just have to beat Territories and B.C. at night so we'll take it."
Northern Ontario had lost three of four going into the game versus Manitoba, but won emphatically. Manitoba curled 91 per cent as a team, but the Sault Ste. Marie foursome one-upped them at 92 per cent.
"We all drank a huge Red Bull before the game, honestly," Jacobs said. "Just feels good to have our back against the wall slightly and come out and play as well as we did, especially after we've been struggling the last few games.
"I think we'd been watching the standings a little bit too much. We just backed off of that and said 'Guys, let's just go out and play like we can' and we had a nice little talk before the game. Everyone just had the eye of the tiger tonight. It was refreshing to see that because we hadn't had that fierceness the last few games."
Jacobs also has two winnable games Friday versus P.E.I. and Nova Scotia.
After losing four of its first five, the host province was giving Rexall Place a reason to keep faith. Four-time Canadian champion Martin edged Saskatchewan 6-5 for a fourth straight win. The Edmonton team faces two formidable opponents on Friday — Ontario and Newfoundland and Labrador.
"It's a faint heartbeat, but there's still a heartbeat," Martin said.
Another notable game Friday is Quebec's Menard, who upset Howard to win the 2006 Canadian championship, versus 2006 Olympic gold medallist Gushue.