Finland and the Czech Republic had difficult starts to the Games. The Czechs lost their opener 5-1 to the U.S. followed by a 4-3 shootout loss to Switzerland.
Finland's first match was postponed after four of their roster tested positive for norovirus and they lost 5-0 to the U.S. on Saturday.
The Finns conceded twice in the opening period on Sunday, Tereza Pistekova and Natalie Mlynkova on target for the Czechs who, unlike against the Swiss, managed to hold onto their two-goal lead.
The Czechs went in front in the third minute, stealing the puck in the neutral zone before Pistekova lifted her shot over the goalie.
Finland could have been in further trouble less than a minute later with Susanna Tapani penalised for hooking, but they managed to kill the penalty
The Czechs were then left shorthanded twice in quick succession, and the Finns peppered Klara Peslarova with shots but the goaltender held firm.
After failing to make two power plays count, Finland conceded again near the end of the opening period, Mlynkova blasting the puck into the roof of the net.
Peslarova made a great save to deny Michelle Karvinen on a Finnish breakaway early in the second period and the Finns pulled their goalie in the final two minutes of the game but were unable to find the net.
The U.S. top Group A with six points after two games, with the Czechs two points behind in second. Champions Canada are on three points after one game, Switzerland have two points and the Finns have yet to earn a point.
All five sides will advance to the last eight, where their seedings will depend on the final placings in the preliminary round.
Check out the full match summary here.
Sweden sweep past France
The Swedes have a maximum nine points after three matches to sit top of the Group B standings, with Germany, Japan and Italy all on three after two games.
France are bottom without a point after three defeats.
The top three will advance to the last eight.
France shipped three goals in the opening period with Thea Johansson, Sara Hjalmarsson and Hanna Thuvik all on target for Sweden, who added a fourth through Lisa Johansson at the start of the second period.
Thea Johansson opened the scoring in the fourth minute, forcing the puck home from Hilda Svensson's pass into the crease for her fourth goal of these Games, the top scorer of the tournament.
France were left shorthanded when Margot Huot-Marchand was sent to the penalty box for tripping and Hjalmarsson converted a rebound shot to double Sweden's lead less than four minutes later. Thuvik added another with a backhander off the crossbar.
Huot-Marchand was given another penalty for an illegal hit, with Sweden failing to make the power play count, but in the opening minute of the second period Lisa Johansson stuck the puck between the legs of the French goalie for the fourth goal.
French forward Lore Baudrit was penalised for roughing, which Sweden's Nicole Hall laughed off, but Hall later spent time in the penalty box for the same offence along with France's Chloe Aurard-Bushee after they clashed behind the Swedish goal.
French fans in full voice
France more than held their own for the remainder of the second period, resisting waves of Swedish attacks, while firing in seven shots, with every foray beyond the Swedes' blue line roared on by the large French contingent in the stands.
Sweden's Mira Jungaker received a minor penalty for interference, shoving Clara Rozier to the ice, with the French fans booing when the replay was shown on the big screen.
France failed to take advantage of the later power play and it was the bright yellow-jerseyed Swedes celebrating in the arena at the final buzzer as the players went to salute their supporters, beating their sticks on the ice.
Sweden play their final preliminary round match against Japan on Tuesday with France facing Germany on Monday.