What happened overnight?
Cristiano Ronaldo, genius.
The World Cup burst spectacularly to life with an enthralling 3-3 draw between 2010 winners Spain and European champions Portugal, with the world's foremost #7 well and truly front and centre.
Twice Portugal went ahead through Ronaldo and twice Spain clawed their way back through Diego Costa, before defender Nacho Fernandez, who had conceded an early penalty, belted in an unstoppable strike to give Spain a 3-2 lead.
But the man many consider to be the world's best, delivered yet again when his country needed him most, firing home an exquisite free-kick to complete his hat-trick and earn Portugal a share of the points.
Late goals were the order of the day in the other two matches.
Egypt looked destined to snatch a precious point in Group A, before Uruguayan defender Jose Gimenez rose to majestically head home his side's winner in the 89th minute.
The Group B opener between Iran and Morocco was also goalless deep into added time, before a late, late own-goal handed Iran all three points.
It took Ronaldo just 130 seconds to make a significant impact at Russia 2018.
He was brought down by Real Madrid club-mate Fernandez as he drove into the penalty area, before clinically dispatching the resulting spot-kick. His second owed plenty to a goalkeeping error (see below), but his third was simply breathtaking. There aren't really any suitable adjectives for what he did today.
Spanish defender Nacho Fernandez had never scored an international goal since debuting in 2013, but in his first World Cup match he smashed home a spectacular winner. When you get the chance, check this one out – it's just a belting goal.
David de Gea is widely regarded as the best goalkeeper on the planet, which made his high-profile error in this game even more incomprehensible. Late in the first half, Ronaldo fired a firm left-footed shot in de Gea's direction, but instead of making what was a relatively straightforward save, Spain's custodian inexplicably allowed the ball to rebound off his hands and into the net.
The story of Moroccan striker Aziz Bouhaddouz is an inspirational one; both his parents died before he was a teenager and he was working at Burger King when he was 18. But when forwards defend, disaster can strike, which it did in St Petersburg when the popular cult hero headed into his own net to hand Iran victory.
Egypt's talisman Mohammed Salah was named among his side's substitutes, but played no part as he continues his recovery from injury with the hope of playing in the next two matches.
They said what?
Uruguay coach Oscar Tabarez: "The experience today will help us grow, but we can't make too much of it. If Mo Salah had been on the pitch, I'm sure Egypt would have benefitted. But we had matches in qualifying without Suarez and Cavani, and that's just how it is."
Ronaldo became the first Portuguese player (and just the fourth overall) to score at four World Cups and the first player to score in eight successive major tournaments (World Cups and European Championships). His was the first ever World Cup hat-trick by any player against Spain and he's now scored 23 goals in his last 18 internationals.
Iran's win was just their second ever at a World Cup; their only previous victory was a 2-1 win over the United States in 1998. The goal that won it for them was just the second injury-time own-goal in World Cup history.
Get the coffee stocked up – it's another busy and exciting night ahead with Groups C and D both getting underway.
Australia face a massive task when they meet 1998 champions France in their first game at 10pm tonight, before 2014 runners-up Argentina welcome World Cup debutants Iceland at 1am.
Having beaten New Zealand in November's intercontinental playoff, Peru make their return to World Cup action for the first time in 36 years when they play Denmark at 4am with Croatia and Nigeria opening their campaigns at 7am tomorrow morning.