* Italy overcome youthful England in absorbing match
* In same group, Costa Rica stun Uruguay with 3-1 win
* Colombia beat Greece 3-0, Ivory Coast defeat Japan 2-1 in Group C
* Qatar issues statement on 2022 World Cup bid
* Sunday Times publishes latest allegations on process
Ivory Coast came from a goal behind to beat Japan 2-1 in the late kickoff in Recife after Colombia overcame Greece 3-0 to open Group C proceedings.
On an action-packed day across Brazil, England against Italy in the searing heat and humidity of Manaus had top billing, and it lived up to the hype in a thrilling contest in keeping with this tournament's emphasis on attacking football.
Claudio Marchisio fired Italy ahead after 35 minutes when England were wrong-footed by an Andrea Pirlo dummy, but Daniel Sturridge levelled within three minutes after Wayne Rooney picked him out with a perfect left-wing cross.
Mario Balotelli, who had a clever lob cleared off the line at the end of the first half, made it 2-1 five minutes into the second when he took advantage of ragged defending to head home.
England pressed for an equaliser, but Italy's defence grew in authority as the match wore on and the Azzurri secured the three points.
"Up until just a few years ago England relied on long balls, but they are now a skilled team with excellent triangular passing," said Italy coach Cesare Prandelli.
"They have changed a lot and now have one of the strongest attacks in the World Cup. That is why I am so satisfied with the result."
Some 2,400 kilometres (1,500 miles) to the east in Fortaleza, Costa Rica came from a goal behind to beat Uruguay 3-1 and blow one of the toughest groups wide open.
Promising young striker Joel Campbell set them on the way, chesting down a cross from the right after 54 minutes and slamming home a low shot to cancel out Edinson Cavani's first- half penalty.
Centre back Oscar Duarte put the Central Americans ahead just three minutes later with a brave diving header at the back post from a Christian Bolanos free kick.
Substitute Marco Urena completed one of most memorable victories in his country's modest footballing history with a third in the 84th minute, silencing an army of sky blue-clad fans who had made the trip north from the River Plate.
To compound Uruguay's misery, defender Maxi Pereira became the first player to be sent off at this World Cup when he was shown a straight red for upending Campbell with a nasty kick to the shin in stoppage-time.
Striker Luis Suarez, recovering from a knee injury, could only look on from the bench and the South Americans will be hoping he is fit for the crunch clash with England in Sao Paulo on Thursday.
The result, an even bigger surprise than Friday's 5-1 trouncing of champions Spain by the Netherlands, extended one of the most exciting starts to a World Cup in living memory.
"I didn't hear anyone saying Holland would be favourites against Spain or that Costa Rica would win," Uruguay coach Oscar Tabarez told reporters.
"But that's what we saw. Once the game starts, everything depends on the mentality of the players."
The goal tally in Brazil is already 28, at an average of 3.5 a game in a free-flowing start to the tournament.
Years of construction delays, alleged corruption and sometimes violent protests over the $11 billion spent by Brazil to host the World Cup have been overtaken by the scintillating action on the field, at least for now.
The buildup to the tournament was also marred by allegations of corruption within FIFA, soccer's governing body, centring on Qatar's successful bid to hold the 2022 World Cup.
The organisers of the bid gave their firmest rebuttal to date of allegations of bribery in a statement they hope will dispel the atmosphere of distrust that has descended on the game in the last few weeks.
Disagreement over the scandal has deepened divisions within FIFA, headed by Sepp Blatter whose expected run for re-election next year is opposed by European member states but supported by those in Africa, Asia and beyond.
"We have nothing to hide ... In every aspect of the 2018/2022 FIFA World Cup bidding process, we strictly adhered to FIFA's rules and regulations," Qatar 2022 said.
Britain's Sunday Times newspaper, which has reported the allegations of bribery in recent weeks, published its latest article in which it said FIFA bosses had been warned in a "secret terror briefing" that there was a "high risk" of a terrorist attack shutting down the event.
A spokesman for Qatar 2022 said he had no comment on that particular report.
In Recife, Japan's Keisuke Honda's fierce left-foot drive gave his side a 1-0 halftime lead but Wilfried Bony levelled with a glancing header in the 64th minute.
Two minutes later Gervinho repeated the trick, this time at the near post, after another inch-perfect cross from the right from Serge Aurier, completing an impressive turnaround.
In the early Group C kickoff, Colombia swept aside Greece in Belo Horizonte, winning even without injured leading striker Radamel Falcao.
In their first World Cup appearance since 1998, it was a reminder that Colombia remain a force to be reckoned with.
The South Americans made a blistering start with left back Pablo Armero scoring with a fifth minute deflected shot. Striker Teofilo Gutierrez stabbed home a flicked 58th-minute corner and midfielder James Rodriguez added a late third goal.
The soccer world was still recovering from the shock of the Netherlands' victory over Spain which included a spectacular header from flying Dutchman Robin van Persie.
"If I was the head of the Dutch airline company, I would sign him up tomorrow and use that image of a Dutchman flying through the air," said Jean-Paul Brigger of FIFA's Technical Study Group. "It was just fantastic."
In Sunday's games, Switzerland play Ecuador in Brasilia and France face Honduras in Porto Alegre in Group E, while in Group F Argentina get their campaign underway against Bosnia in Rio de Janeiro.