Simmons beat Switzerland's Marc Pfister 8-4 in the morning draw and topped Scotland's Ewan MacDonald 7-1 in the evening at Scotiabank Centre. The Canadian team of Simmons, third John Morris, second Carter Rycroft and lead Nolan Thiessen will take an 8-1 record into the final day of round-robin play Thursday.
"I'd say we're playing a good A game," Morris said. "But we want to get to an A-plus game."
Defending champion Thomas Ulsrud dumped Jiri Snitil of the Czech Republic 12-5 to join Canada in a first-place tie and secure the other 1-2 game berth. Ulsrud and Simmons will meet Friday night with a spot in the final on the line.
The third and fourth seeds will meet in Saturday's 3-4 game with the winner to advance to the semifinal against the loser of the 1-2 game. The semifinal winner will play for gold and the loser will play for bronze.
The medal games are set for Sunday. The Canadians, who suffered their only loss to Ulsrud on Tuesday night, are hoping to return to the podium after settling for a fourth-place finish last year in Beijing.
"That's a great team and they're the defending world champions," Thiessen said. "Was it (pro wrestler) Ric Flair who said, 'To be the man, you've got to beat the man?' So that's what we've got to do."
Simmons was in form from the start against Scotland, picking up steals in the first three ends for an early 3-0 lead. MacDonald got one back in the fourth with an open hit but Simmons answered with another single in the fifth end.
Canada took a 5-1 lead in the sixth end and the teams blanked the seventh. MacDonald conceded after giving up a steal of two in the eighth end.
"You're playing for pride out there when you're playing Scotland," Morris said. "It was just good to see us come away with the W and keep the pressure on Ewan most of the game, and eventually he showed a few cracks."
Sweden's Niklas Edin, the 2013 world champion, picked up two victories to move into sole possession of third place at 6-3 while Switzerland lost twice to fall into a fourth-place tie with Finland's Aku Kauste at 5-4. Kauste edged China's Jialiang Zang 8-7 in an extra end.
American John Shuster and Japan's Yusuke Morozumi were next at 4-5. Canada will play Finland and Italy on Thursday.
In the morning victory, Simmons hit a takeout to score three in the fourth end and stole two more points in the fifth to put the game out of reach.
"I'm happy to see that we bounced back," he said. "We were ready to play this morning against a good team and managed to play pretty well."
With the game well in hand, Canadian alternate Tom Sallows replaced Rycroft in the seventh end.
Canada opened the round robin with six straight victories before falling to Ulsrud. The Norwegian skip defeated Italy's Joel Retornaz 9-2 in the minimum six ends in his morning game.
"We got a good start and picked up from where we left off yesterday against Canada," Ulsrud said. "We have a lot of confidence in the ice and it's really coming together right now.
"The only thing I'm worried about right now is the guys peaking too early in the week, so we just have to keep it going."
Several groups of schoolkids watched the morning action from the upper level of seats. That helped boost attendance to 1,680 at the 10,500-seat venue.
Only 1,237 fans took in the afternoon action. Attendance rose to 3,052 for the evening draw with Canada back on the ice.
China, Italy, the Czechs and Scotland were tied at 3-6 after 14 draws. Russia was last at 2-7.
Glenn Howard was the last Canadian skip to win this event. He took the gold at the 2012 competition in Basel, Switzerland.
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