Brazil kicked off their campaign for their first women's football Olympic gold with a convincing 3-0 victory over China at the Olympic Stadium in Rio de Janeiro.
It was a successful day for all the favourites, as Sweden, Canada, Germany, France, and the United States of America all picked up three points in their opening fixtures.
The hosts were keen to get things underway, and a first-half header from Monica, plus second-half goals from Andressa Alves and Cristiane, took the pressure off Vadao's team.
Brazil took the game to the Chinese, asking a lot of questions of their defence. Striker Cristiane had chances, forcing Zhao Lina into an excellent save before seeing Tan Ruyin clear another attempt off the line.
Late in the first half, China failed to clear a corner, and Monica was on hand to powerfully send her header into the net from the edge of the box.
With the pressure off, the hosts began to play some nice football. A lovely pass over the top from Andressa found the devastating Marta free on the right, she controlled well before setting up Andressa Alves on the edge of the six-yard box.
Andressa was again the creator late on, playing in a curling free-kick to the back post, and legendary forward Cristiane was there to nod in the third.
That was the striker's 13th goal at the Olympics, meaning she has scored in four straight tournaments and has found the net more than anyone else.
Earlier in Group E, Sweden kicked off the tournament with a 1-0 win over South Africa, but there were elements of their play that seemed reminiscent of their poor performance in Canada 12 months ago.
Pia Sundhage's team were dominant for large spells of the match, with Sofia Jakobsson hitting the crossbar early in the game.
Lotta Schelin also went close, testing the South African 'keeper, Roxanne Barker, who made a superb save.
Sadly, it would be Barker at fault for the only goal of the game. She failed at two attempts to both clear a cross and handle the cross, leaving Nilla Fischer the easy job of turning the ball over the line.
“When you play such a quality team they’re going to punish you for it,” South Africa captain Janine van Wyk told the press after the game. “It was a bit unfortunate, we don’t think that Sweden deserved the three points at all. If anything, it could’ve been a draw.”
Vera Pauw's inexperienced side will take heart from the performance. The Banyana Banyana forced Hedvig Lindahl into a save in the second half, and the narrow loss shows how far they've come in the last four years.
Canada got their Olympic games off to a blistering start on Wednesday when they took the lead against Australia after just 20 seconds.
Christine Sinclair capitalised on a mistake from Laure Alleway, then squared the ball to Janine Beckie and she made no mistake, scoring the fastest goal in Olympic Football history.
That beats the old record of 30 seconds, set by Mexico's Oribe Peralta four years ago in the Gold medal match against Brazil.
After the game, Matildas coach Alen Stajcic, while praising the Canadian defence, was critical of his own players and their second-half performance. "We just weren't good," he said, reports Canadian journalist Neil Davidson.
His team should have stood more of a chance when Shelina Zadorsky was given a red card after just 19 minutes, bringing down Michelle Heyman as the Australians were on the attack.
As Australia pushed forward, Canada took their moment and sealed the 2-0 victory. A great ball from young Jessie Fleming found Christine Sinclair, one of the great forwards in women's football history. Her first touch was perfect, taking the ball around Lydia Williams, and then she guided the ball into the net with 12 minutes remaining.
Unsurprisingly, John Herdman, Canada’s coach, was much happier with the performance and the result.
"The game had a bit of everything," he said to the Canadian Press (via Yahoo Sports). "It was great to watch."
Germany’s quest for an Olympic medal got off to an impressive start in Sao Paulo, beating the minnows Zimbabwe 6-1.
There were two moments of concern for Silvia Neid’s team: Simone Laudehr had to come off injured in the first half following a terrible tackle from Lynett Mutokuto, and German goalkeeper Almuth Schult will want to have done much better for the Mighty Warriors' goal.
Rutendo Makore curled a right-footed shot from the edge of the box; Schult should have dealt with it better, but she only managed to parry it into the path of Kudakwashe Basopo.
It was a great moment for the 26-year-old striker, scoring her country's first goal at the Olympics, but Germany will feel it’s a goal that could have been avoided.
Outside of that blip, there were some excellent goals from the Germans. Alexandra Popp jumped highest to head in Melanie Leupolz’s hanging cross to make it 2-0 at half-time, after Sara Dabritz opening the scoring.
Melanie Behringer would score the game’s best goal. It came just moments after Basopo had made it 2-1, and the Bayern Munich player curled a wonderful free-kick into the far top corner. The instant reaction all but ended Zimbabwe’s chances of a comeback.
She would make it 4-1 with 12 minutes to go, although missing the initial penalty kick, she was quick to react and volleyed home the rebound. Leupolz would make it five, controlling the ball inside the area to score from close range; late in the game they would make it six when Eunice Chibanda headed Lara Goessling’s cross into her own net.
A dominant performance from the top ranked European side, but they will have much tougher tests to come.
France were Wednesday night’s most convincing winners, beating Colombia 4-0 without ever feeling under pressure.
It was only last year when the South American side beat them in the group stage of the World Cup, out-fighting Les Bleues all over the pitch. Philippe Bergeroo’s team would come out flying this time, taking the lead after just 70 seconds.
Eugenie Le Sommer drove in a low cross from the right, and a slight touch from goalkeeper Sandra Sepulveda put the ball into the path of Carolina Arias. The goalkeeper couldn’t move her leg quick enough and could only watch as it found the back of the net.
Le Sommer would make it 2-0 after a quarter of an hour, converting the rebound after Camille Abily’s high shot came off the crossbar.
France dominated for huge spells of the game, controlling the tempo and keeping the Colombians from finding any rhythm. Abily’s deadly free-kick made it 3-0 before the break. Amel Majri would then raise the bar, firing her own set piece high into the top corner.
Next up for France is a clash with the reigning gold medalists and world champions USA in Belo Horizonte, and they, although less convincingly, got their tournament off to a winning start by beating New Zealand 2-0.
Jill Ellis’ team were guilty of starting slowly in Canada last year, but there were no repeats here, as they came out ready to play, taking the game to the Football Ferns and taking the lead through a Carli Lloyd header after just nine minutes.
"That was the best way we could have started," said Tobin Heath, who set up Lloyd for the opening goal, according to the Associated Press (via NBC). "We came out with a lot of energy and a lot of determination. I think in that regards we put our best foot forward and got that goal and I think that helped propel us throughout the game."
New Zealand held strong and refused to crumble under the pressure, and although they couldn’t quite trouble the USA defence, they held the score at 1-0 until half-time.
Tony Reading would have been distraught when his team conceded a sloppy second just minutes after the restart. Poor defending let Alex Morgan receive a pass from Morgan Brian, and the Orlando Pride forward drilled the shot past Erin Nayler’s near post. It was a poor goal to concede.
The result put three points on the board for the USA, but they will hope to improve in the final third as the tournament progresses. With what France, Germany and Brazil showed in their opening games, they might have to.