Brazil will start the pool as the favourites, while Cameroon, Croatia and Mexico will all be hopeful in what is, on paper, a wide-open fight for a second spot in the knockout phase.
A fiercely disputed 96th-minute Eden Hazard penalty gave Chelsea a 2-2 home draw with West Bromwich Albion to save Jose Mourinho's unbeaten home record, while Liverpool cruised at home to Fulham.
FIFA.com wraps up Wednesday's UEFA Champions League action headlined by Lionel Messi's return to goalscoring form as Barcelona and Atletico Madrid became the latest teams to reach the knockout stage.
La Liga duo Barcelona and Atletico Madrid both booked a spot in the UEFA Champions League last-16 with wins over AC Milan and Austria Wein, while Arsenal picked up a hard-fought win at Borussia Dortmund.
With AC Milan and Barcelona having become very familiar with each other in recent seasons in the UEFA Champions League, FIFA.com looks back at some of the classic encounters between this pair of European giants.
Arsenal regained the top spot in the English Premier League with an impressive 4-1 win over Norwich City, Chelsea clipped Cardiff City by the same scoreline and Manchester United surrendered a late 1-1 draw to Southampton.