Following Saudi Arabia's seismic result against Argentina on Tuesday, the shocks continued on Wednesday, while Spain laid down a marker and Canada proved they belong.
Here are the main talking points from the fourth day of the 2022 World Cup.
Japan show class on and off the pitch
Perhaps it wasn't quite as earth-shattering as Saudi Arabia's win over Argentina, but Japan kept the shocks coming in Qatar by coming from behind to beat Germany 2-1 and provide another boost for Asian football.
There were some curious similarities between both results, too: Saudi and Japan both went behind to first-half penalties before striking two quick goals in the second half to secure famous victories.
Like Saudi, Japan have been a perennial powerhouse of Asian football for quite some time, qualifying for each of the past seven World Cups and three times advancing from the group, although they are yet to reach the quarter-finals.
Drawn in a tough Group E which also includes a Spain side clearly in the mood (more on them in just a moment), Japan have given themselves a great chance of another knockout appearance. Beat a hapless looking Costa Rica in their next game and if Germany fail to beat Spain, then Japan are through with a game to spare.
After proving their quality on the pitch, Japan then showed their class off it. Photos emerged of an immaculate changing room after the squad had left, while the fans continued one of the best traditions in football by staying behind and helping to collect litter around the stadium.
Given their impact on the World Cup so far, few neutrals will be rooting against Japan to have a good tournament.
Spain lay down a marker
During the pre-tournament predictions forecasting which nation would win the World Cup, Spain were not even in the conversation. Brazil and Argentina, sure. There were solid arguments for England, Portugal, Germany and France, too, even with the latter's injury crisis. But Spain? Forget it. They don't even have a world class striker and their form has been too patchy.
Yet, Spain's performance against Costa Rica on Wednesday, a 7-0 decimation at Al Thumama Stadium, showed Luis Enrique and his players mean business. Admittedly, Costa Rica were shambolic but Spain were superb, combining their clinical finishing with a passing game that left their opponents chasing shadows.
In Barcelona trio Pedri, Gavi, and Sergio Busquets, Spain have one of the finest midfields in the competition, they have a talented and tricky attack with the likes of Marco Asensio, Dani Olmo and Ferran Torres, and have sneaky strength in depth: among their substitutes on Wednesday were Ansu Fati, Koke, Alvaro Morata, and Carlos Soler.
Bigger tests than Costa Rica await Spain - none more so than Germany in their next group game - but so far so good for La Roja.
Canada prove they belong
Canada played their first World Cup game in 36 years on Wednesday, taking on European giants Belgium in their Group F opener.
It was meant to be a nice, gentle introduction to the tournament for a Belgium side ranked second in the world - compared to Canada's 39 - and boasting some of the best players in the world, headlined by midfield superstar Kevin De Bruyne.
Belgium ultimately got the win and three valuable points, but it could have been very different thanks to an impressive performance by Canada, who utterly dominated the first half and had a penalty saved by Thibaut Courtois.
Were it not for some wasteful finishing, Canada could easily have joined Saudi Arabia and Japan as surprise winners this week.
Despite the result, it was an encouraging performance which proved Canada certainly deserve to be mixing it among the world's best teams. With young stars including Alphonso Davies, Jonathan David, and Tajon Buchanan - who was brilliant against the Belgians - the future of Canadian football looks exciting.
But even looking at their immediate future, in a group that contains Morocco and Croatia - who played out a goalless draw - Canada can give themselves a fighting chance if they are able to replicate Wednesday's performance for the rest of the group stage.
