First Japan, ranked 61st in the world, became the first Asian side to beat South American opposition at any World Cup, overcoming 16th-ranked Colombia 2-1.
ThenSenegal claimed Africa's first win of this tournament, beating Poland 2-1.
And hosts Russia all but secured their progress to the knockout stages, beating Egypt 3-1, with all the goals coming in the second half.
Heroes Russia. Anyone pick the home side to win their first two games, scoring eight goals in the process? Nope, me either, but they've done just that and now have momentum and an entire nation behind them.
A difficult round-of-16 game awaits against (probably) one of Spain or Portugal, but would you want to play a rampant Russia at the moment?
Meantime, Senegal front-man M'Baye Niang was waiting on the sideline after being treated for injury when the move that led to his side's second goal started.
Where's the goalie? Senegal's Niang scores in an empty net. Photo / FifaTV
Polish protests fell on deaf ears and replays showed the referee clearing inviting Niang back onto the field, where he made his immediate and crucial impact.
Villains After less than 200 seconds of their opening match, Colombia were down to ten men when Carlos Sanchez handled Shinji Kagawa's goal-bound effort and was not only sent off, but conceded a penalty from which Kagawa put Japan ahead.
Meantime, Brazilian-born defender Thiago Cionek became the first Polish player to score an own-goal at a World Cup when he deflected a goal-bound effort into his own net to give Senegal a lead they never relinquished.
And Egyptian defender Ahmed Fathi also scored an own-goal to put his side 1-0 down against Russia, taking the total number of own-goals at this tournament to five, already second only to France 1998 when there were six.
They said what? Japan coach Akira Nishino: "This is just one win and three points, so we will save our celebration."
Poland striker Arkadiusz Milik: "We played very badly today. It was one of our worst performances for a long time. We did not create any chances. Senegal built a wall and we were not able to jump over it. I'm not sure if Senegal played well or we were so bad."
Stat chat This is the first World Cup since 1974 in which four South American teams have failed to win their opening game.
Japan's second goal was the first they'd ever scored from a corner in 18 World Cup matches.
Poland now haven't kept a clean sheet in any of their last nine World Cup matches, since beating Portugal 1-0 in 1986.
Star player Mohamed Salah had fewer touches than any other Egyptian outfield player in the first half against Russia.
Did you know? The red card shown to Carlos Sanchez was the first of this tournament and the second quickest in World Cup history after Jose Alberto Batista for Uruguay vs Scotland in 1986 (54 seconds).
It was also the first time in history that a team's first foul in a World Cup match has led to a sending-off.
What's next? The second games in Group B happen tonight with Portugal facing Morocco at midnight and surprise table-toppers Iran meeting Spain at 6am.
In between those two matches, Uruguay look to secure their passage to the knockout rounds when they clash with Saudi Arabia in Group A from 3am.
