Three games takes place with the headline fixture a repeat of the 2010 final as Spain take on Holland.
We also have our verdict on the opener between Mexico and Cameroon and the later kick-off, Chile v Australia.
Check out our match-by-match verdict below.
This pair are the perceived makeweights in Brazil's pool and although not one of the marquee fixtures in the tournament, it will be an interesting tactical affair considering a defeat for either at this early stage may well mean curtains with Croatia and the hosts up next.
Not for the first time the build-up for the Indomitable Lions has not gone particularly like clockwork with the players 20 hours late arriving in Brazil having threatened not to travel following a dispute of bonus payments.
Their football team will always be remembered for their exploits at Italia 90 when Roger Milla ran rings around defences on the way to becoming the first African nation to reach the last eight - where they were ousted by England.
But those memories are starting to fade a little. They have managed only one win at a World Cup since and the feeling is that this will be one of the weaker squads they have assembled for the tournament.
Leading scorer Samuel Eto'o remains the talisman in what will be his fourth finals and though he enjoyed a reasonably successful campaign with Chelsea, it does rather highlight how little progress they have made in terms of fast-tracking some fresh talent.
One player potentially of interest is midfielder Stephane Mbia, who is worth a speculative look at 20/1 for a goal at some stage.
Once of Harry Redknapp's parish at QPR, Mbia is highly unlikely to be back in west London after a fantastic season with Sevilla on loan which ended in triumph in the Europa League.
He is not the most prolific in front of goal but he is a dynamic performer who can get into the penalty area and exploit a Mexican midfield and backline that can be pushed around by a more physical outfit.
It is hard to be overly-critical of Mexico coach Miguel Herrera having not lost in six games since taking over. But this will be his first real test against quality opposition, while his reliance on players from their own domestic league could be found out, although Santos Laguna striker and Olympic final hero Oribe Peralta is highly regarded and one to watch with a tremendous recent scoring record for El Tri.
A watching brief is probably a good idea in all honesty in terms of the win market until we have had a chance to appraise the merits of these two but if pushed, I would just give the edge to Cameroon with Mbia hopefully making an early name for himself.
Oribe Peralta has scored eight goals in his last six competitive appearances for El Tricolor.
Mexico have never beaten at African team at a World Cup finals tournament, losing one and drawing two of their three meetings against sides from that continent so far.
This is only the second ever meeting between these two countries; Mexico won the first clash 1-0 in a friendly in 1993.
Cameroon have only won one of their last 13 World Cup games (1-0 v Saudi Arabia in 2002), drawing four and losing eight.
BEST BET: Stephane Mbia to score first at 20/1
A repeat of the last World Cup final is undoubtedly the game of the day but one which looks harder to get a full handle on.
The holders should have too much class and I do wonder whether a shade under even money about a win for them could look a great bet with hindsight. Win this and they won't be that price again until the latter stages.
They have lost just two of their last 36 matches - one in the final of last year's Confederations Cup to Brazil and the other away to South Africa in a friendly last November.
However, I also feel that people have been writing off Holland a little too easily. This is the nation which almost lifted the trophy four years ago.
OK, much has changed in their squad since then but top-quality performers such as Arjen Robben and Robin van Persie remain which, as usual, the youngsters coming through all know how to use the ball well and possession will be key in a tournament in which the conditions will play a major factor.
Having said that, a draw will suit the Dutch just fine in this one and I can see them defending deep, happy to leave Spain to knock the ball around themselves.
With Robben and van Persie further forward, counter-attacking football could pay dividends and it is worth remembering that Holland scored more goals in European qualifying (34) than any other bar Germany.
Vicente Del Bosque has only lost one of his 25 World Cup games as Spain head coach, including qualifiers (W22 D2). That was against Switzerland (0-1) in 2010.
David Villa - Spain's top scorer at World Cup Finals (eight goals) - has been directly involved in seven of Spain's last nine goals in the tournament (six goals, one assist).
Robin van Persie was the top scorer in the 2014 European World Cup qualifiers (11 goals).
The defending champions have only won their first game in three of the last 10 World Cups (D4 L3), with Italy drawing 1-1 with Paraguay last time out.
BEST BET: Spain to beat Holland by one goal at 5/2
In the run-up to the World Cup, the view on these two teams has been almost universal - Chile are dark horses; Australia whipping boys who will do well to get anything in what is one of the toughest groups.
It seems a fair assessment. Only Argentina scored more goals in South American qualifying than Chile, who have some quality performers at their disposal such as Barcelona's Alexis Sanchez and Juventus' Arturo Vidal.
Since then, they've impressed in beating England 2-0 at Wembley and also were unlucky not to take something from a friendly in Germany which in the end they lost 1-0.
In contrast, Australia won just three matches in a qualifying group containing Japan, Iraq, Jordan and Oman since booking their flight to Brazil have suffered some awful results.
France and Brazil both put six past them, while they shipped four and three respectively to China and Japan at last summer's East Asian Cup. Blowing a 3-0 lead to lose 4-3 to Ecuador in March also took some doing.
Make no mistake, this is not a team packed full of Premier League talent such as the one which headed to Germany in 2006.
Presumably it is Australia's inability to keep sides out which has left boss Ange Postecoglou vowing to have a go at his group rivals. He says it is not a damage limitation exercise.
However, such an approach could well play right into the hands of Chile whose attacking flair makes them a real threat on the counter-attack.
In his ante-post World Cup specials preview, my colleague Ben Coley has already suggested this could well be a high-scoring game and I completely agree.
My way of seeking a profit is to back Chile in the half-time, full-time market in which they are offered at 5/4.
The South Americans are fast starters. Eight of their nine wins in qualifying saw them leading at the interval (in contrast, Australia were ahead at the break in just three of their 14 qualifiers). They also netted early against England and if they get ahead early here, I fear for the Aussies.
Odds-against quotes seem more than fair to me and should be taken.
The Socceroos have only won two of their 10 games at the World Cup (D3 L5) - these coming against Japan in 2006 (3-1) and Serbia in 2010 (2-1).
Chile conceded 1.56 goals per game in the qualifiers, more than any other of the 32 participants in the 2014 edition.
Australia have never beaten la Roja in any competition, drawing one and losing three so far.
Arturo Vidal was the top scoring midfielder in South American qualifying, helping himself to five goals.
BEST BET: Chile to beat Australia half-time/full-time at 6/5
- Posted at 1645 BST on 12/06/2014.