Highlights - Argentina 1-0 Nigeria
Argentina coach Diego Maradona said his side's 1-0 opening World Cup win over Nigeria will ease their nerves.
Gabriel Heinze's header gave the South Americans a deserved but ultimately hard-fought victory over the Super Eagles in Group B on Saturday.
"To begin a World Cup in winning fashion gives you a certain sense of calmness," said Maradona.
"The only thing that concerns me is that we won a big match. Thank God we won the game."
Maradona's talented side came into the tournament off the back of a turbulent qualifying campaign and with suggestions that the coach's inexperience and perceived eccentricity would hamper their challenge.
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But in an Ellis Park stadium full of blue-and-white shirts and adorned with banners of Maradona, the suited Argentine coach cut a typically animated and passionate figure on the touchline during an engrossing game his side dominated.
Heinze's 12-yard diving header from a Juan Sebastian Veron corner was the only goal of the game but the Lionel Messi-inspired South Americans should have had more.
But for the Nigerians wastefulness in front of goal, Argentina would have been made to pay for their inability to kill the game off.
"The team made good moves but we ended up suffering. That's the law of football," said Maradona.
"They let us off... If we'd taken our chances the course of the match would have been different."
The coach was also full of praise for Fifa World Player of the Year Messi, who has often being accused of failing to reproduce his club form on the international stage but was central to his side's impressive display at Ellis Park.
"He was very close to the ball [at all times]," said the coach about the man often burdened with being former midfielder Maradona's natural heir in the Argentine side.
"Football wouldn't be beautiful without seeing Messi touch the football," added Maradona.
Maradona is bidding to become only the second man - after Germany's Franz Beckenbauer - to win the World Cup as a player and coach.
The former Barcelona and Napoli midfielder famously inspired his side to World Cup glory as a player in Mexico in 1986.
"This was an important step we took today [but] we have to improve a lot of things to get to the seventh match [the final]," added Maradona.
His side next face South Korea - who beat Greece 2-0 earlier on Saturday - on 17 June before a final group fixture against the Greeks on 22 June.
Heinze hits home for Argentina