Mexico overcame having two goals controversially ruled out to beat Group A rivals Cameroon courtesy of a strike from forward Oribe Peralta.
Giovani Dos Santos had a volley and a header disallowed, with replays suggesting both calls were incorrect.
Cameroon rarely threatened but a Samuel Eto’o shot hit the post and Benoit Assou-Ekotto’s free-kick went wide.
However, Mexico secured victory when Dos Santos’s shot was parried before Peralta arrived to slot in the rebound.
At a rain-lashed Estadio das Dunas in north-eastern city Natal, Cameroon almost stole a point late on when Benjamin Moukandjo’s free header was acrobatically saved by keeper Guillermo Ochoa.
An equaliser would have been harsh on a Mexico side who put on an impressive performance, combining a strong work ethic with an attacking threat, and should serve them well when they play hosts Brazil on Tuesday, 17 June.
Peralta’s seventh goal in nine competitive games prevented the dubious refereeing decisions from overshadowing the victory, while Cameroon’s quality and prospects of getting into the second round appear limited with Croatia and Brazil to come.
There were questions about how these countries would fare, with both sides changing managers in scraping through World Cup qualifying.
A nimble Mexico, though, appeared determined to make the most of their time in Brazil, while a powerful-looking Cameroon showed their struggles had continued into the tournament.
The African side struggled to deal with the wing-backs in the 5-3-2 formation employed by the Aztecs, who appeared to have a legitimate early goal disallowed.
Giovani Dos Santos shows his frustration at having a goal disallowed against Cameroon
Hector Herrera crossed from the right and forward Dos Santos scored a left-foot volley only for the effort to be ruled out for offside, even though replays showed the strike should have stood.
Cameroon almost made it worse when left-back Assou-Ekotto followed up a marauding run by picking out Eto’o, whose first-time shot hit the outside of the post.
Mexico might have felt annoyed they were not in front and their grievances were added to when they had another goal controversially disallowed and a penalty shout rejected.
First, Dos Santos’s header from a corner was ruled out, then the striker had a penalty shout turned down following a challenge from Aurelien Chedjou.
However, Mexico had only themselves to blame for not taking the lead just after the break. Dos Santos helped on a pass to release Peralta only for the striker to have his shot saved by onrushing keeper Charles Itandje.
The miss was almost punished when Assou-Ekotto’s free-kick deflected just wide before Mexico’s frustration turned to joy.
A Dos Santos shot was initially parried by Charles Itandje but Peralta was on hand to drive in the loose ball home for the winner.
Mexico coach Miguel Herrera:
“The team surpassed my expectations on the pitch. The attitude was wonderful. The team showed they were mentally strong.
“At no time did we think about the referee during half-time. Never at any time did the team lose concentration.
“We had a lot of opportunities to score goals and we ran hard. I’m thrilled because the team worked collectively and left everything on the pitch.”
Cameroon coach Volker Finke:
“The conditions are the same for both teams so we can’t complain about the weather.
“The pitch itself wasn’t too bad. It’s a pity we didn’t win but both teams had balanced chances.
“We have five days to recover. We will analyse this together because the match against Croatia is very important if we want to stay alive.
Netherlands rout Spain
Netherlands produced one of the biggest shocks in World Cup history by coming from behind to annihilate reigning champions Spain in a stunned Arena Fonte Nova.
Spain lived up to their favourites tag by opening the scoring through a Xabi Alonso penalty, but Robin van Persie equalised with an incredible diving header just before half-time and Arjen Robben put Netherlands in front with a cool finish.
Stefan de Vrij forced in a third from Wesley Sneijder’s free-kick, Van Persie dispossessed goalkeeper Iker Casillas to make it four and Robben’s brilliant solo effort sealed the win.
Spain, looking to win a fourth consecutive major international trophy, were humbled and humiliated in the repeat of the 2010 World Cup final. The last time they conceded five goals in an international match was in 1963 – and it might not only be a fatal blow to their hopes in this tournament, but it could signal the end of an era for one of the game’s greatest teams.
Three-time runners-up Netherlands will suddenly find themselves talked about among the leading contenders to lift the title and it is not unrealistic if they maintain this level of display.
It was their first meeting with Spain since the showpiece four years ago and the first time the previous finalists had met in the opening round of matches at the next World Cup.
Ear-splitting noise reverberated around one of Brazil’s most impressive stadiums as the teams emerged before kick-off.
Netherlands striker Robin van Perise scores a spectacular header against Spain
Van Persie has 10 goals in his last nine Netherlands outings
Costa was clattered early on by Ron Vlaar, and there were more heavy challenges as the first half progressed, but any idea that the Netherlands would turn this into an encounter as brutal as that witnessed in Johannesburg were soon dismissed.
Indeed, it was Louis van Gaal’s men who created the first clear chance when Robben slipped Wesley Sneijder clean through, captain Casillas saving his side with a one-handed save.
That miss appeared costly when Xavi released Costa and he fell under the challenge of De Vrij, Italian referee Nicola Rizzoli pointed to the spot despite replays showing Costa had stood on the Feyenoord defender’s leg.
Alonso slotted past Jasper Cillessen to cue Spanish celebrations – but rather than leading to a period of dominance, Vincent del Bosque’s men sat back and tried to defend their lead.
After David Silva wasted a glorious opportunity that would come back to haunt Spain, Netherlands accepted the invitation to get forward and finally enjoyed some possession.
They grew in confidence and stunned Spain when Van Persie escaped the attentions of Sergio Ramos and met Daley Blind’s crossfield pass with an astonishing header that looped over a despairing Casillas. The goal will be shown again and again for years to come.
Van Gaal’s men deservedly took the lead when Xavi – the heartbeat of Spain’s midfield for so long – lost possession and Blind supplied another pinpoint aerial pass from the left, which Robben controlled before eluding Gerard Pique and finishing confidently.
Spain were now rocking and Van Persie fired against the bar before De Vrij bundled a third goal over the line after Casillas missed Sneijder’s set-piece.
The goalkeeper protested that he had been impeded by Van Persie – and he had a point – but Rizzoli was unmoved and the Netherlands were suddenly in control.
Netherlands forward Arjen Robben scores against Spain in his side’s 5-1 win
Robben has seven goals for the Dutch in his last seven games
Casillas had endured a torrid evening and it deteriorated further when he miscontrolled a backpass and was tackled by Van Persie, who was greeted with an empty net.
Silva had a strike disallowed for offside but was then guilty of poor control, allowing Robben to counter-attack, outpace Ramos and wrap up the scoring with one of the great World Cup goals.
Spain were in pieces and continued to be torn apart, substitute Jeremain Lens and Robben going close. Substitute Fernando Torres looked certain to register a consolation, only for Blind to arrive with a timely last-ditch challenge.
The full-time whistle was met with scenes of Dutch joy and Spanish woe, on the turf and in the stands. Netherlands embarked upon a lap of honour.
It was a result that will send shockwaves through world football.
Chile go past Australia
Alexis Sanchez scored one and made another as Chile started their World Cup campaign with a win over Australia.
Sanchez finished from close range in the 12th minute and then set up Jorge Valdivia to drive in from outside the area two minutes later.
Former Everton midfielder Tim Cahill pulled one back with a header from Ivan Franjic’s cross before half-time.
Former Everton midfielder Tim Cahill has now scored competitive goals on all six footballing continents. (source: official Everton statistician Gavin Buckland)
The New York Red Bulls player, 34, has scored four of Australia’s nine goals in World Cups and has found the net in three different tournaments.
After an anxious second half, Wigan’s Jean Beausejour’s long-range effort added Chile’s third in added time.
Tipped by many as having a strong chance of progressing from Group B, Chile will have been buoyed by the Netherlands’ 5-1 win over Spain, who they face on Wednesday.
They looked likely to have the luxury of focusing on building a big cushion of goal difference ahead of their meeting with Vicente Del Bosque’s world champions when they moved two ahead inside 14 minutes.
But, up against Chile defenders Gary Medel, used in midfield by Cardiff, and Gonzalo Jara, who has just been released by Nottingham Forest, Cahill’s threat in the air helped stubborn Australia back into the contest.
Chile’s attack only justified its strong reputation in flashes and they looked far from secure at the back but they have a chance to take a big step towards the second round when they face Spain.
Cahill’s tally of four World Cup goals is more than Cristiano Ronaldo and Lionel Messi’s combined tally of three
They took the lead when Charles Aranguiz managed to get in behind the Socceroos defence for the first time after 11 minutes, and when Eduardo Vargas headed down from the midfielder’s cross, Sanchez guided in at the near post.
The advantage was doubled when Barcelona forward Sanchez picked out Valdivia and the Palmeiras midfielder hit a dipping shot in off the underside of the bar from 25 yards.
Starting just five weeks after knee surgery, midfielder Arturo Vidal drove wide after another incisive move.
But a slackness crept into their play and Cahill, renowned for his aerial ability in his time at Everton, rose above Medel to thump in from a Franjic cross.
The 34-year-old New York Red Bulls player was then denied by a low save from Bravo after he was found by Mathew Leckie on the edge of the area.
After the break, Cahill had an effort ruled out for offside before Tommy Oar’s cross was met with a firm half-volley from Bresciano only for Bravo to push around the post.
Chile came close to a third when Sanchez threaded through for Vargas and the Valencia forward’s poked effort was hacked off the line by Alex Wilkinson.
Cahill headed over from another Jason Davidson cross as Australia continued to threaten.
But after Mauricio Panilla’s shot was saved by Matthew Ryan, fellow substitute Beausejour found the corner with the rebound.
Chile coach Jorge Sampaoli:
“We had a good understanding in attack, especially with Alexis Sanchez as the focal point, and we created several chances. After Australia scored we lost a little bit of momentum and we got frustrated.
“We didn’t play as well as we can – and with the calibre of our next two opponents, we will have to give a more complete performance. The prospect of playing Spain at the Maracana is electrifying.”
Australia captain Tim Cahill:
“They got in twice and punished us but after that you could see their legs were going and we knew we could get something from this game.
“We really stood up strong. Not a lot went our way and it showed.
“It’s all about defining moments. This is the stage to do it and when you’re called upon you have to show up. We showed a bit of fear but we got in their faces. We showed some aggression, we’ll learn from this and go into the next game positive.”