Lionel Messi hailed Argentina's winning start to the World Cup after scoring a classic goal to see off Bosnia-Herzegovina.
Messi's trademark run and strike will go down as one of the great World Cup goals, but the Argentina captain admitted he was relieved the team had secured a 2-1 win in the Maracana after a disappointing first half.
Argentina had taken a lead in the third minute with a touch of fortune, Sead Kolasinac deflecting the ball into his own net, before Messi scored a stunning second after a superb run to make it 2-0.
Substitute Vedad Ibisevic grabbed a late goal for Bosnia - which could yet prove important in terms of qualification from Group F.
Messi said: "It's important that we started off on the right foot with the three points, but we do have things we must improve.
"It's not easy with all the anxiety and the nerves, but the important thing is the result. We had a great second half. We had the ball much more, created several opportunities and that's what we have to continue to do."
Argentina coach Alejandro Sabella only awarded his team a mark of six out of 10 and said his half-time changes to provide more support to Messi had been crucial.
Sabella said: "On balance I would give it a six. We need to improve and part of that is in my hands - it is up to me.
"The changes at half-time just produced this improvement. They were playing better together and there was more support around Messi. Once Messi received the ball there was better follow-up and better support.
"I think that, whatever happens in this World Cup, he is among the best players in the history of football."
Messi himself acknowledged the changes from five in defence to a 4-3-3 formation made it much easier for him and fellow striker Sergio Aguero.
He said: "As strikers, we prefer that system as it gives us more attacking opportunities and if we don't use that system we suffer a bit.
"I was often on my own and so was Kun [Aguero] and it was very difficult, so there are things to be improved on."
Sabella confirmed that he had taken Aguero off as he had seemed tired rather than for injury reasons, even though the Manchester City frontman had appeared to be limping.
Bosnia coach Safet Susic was satisfied with his team's performance in a match which he said had been settled by one of the best players in the world of all time.
Susic said: "We are realistic people and our goal was to put as much resistance as possible to one of the favourites to win the title, and this is what we have done.
"I am satisfied with what I saw, especially after we had this misfortune to concede an own goal in the first couple of minutes.
"It is a huge satisfaction to take part for the first time in the World Cup and play against a great team and one of the best players in the world - and not only of today but of all time.
"We have still two games to play and I told my players this was not the key match, that we could afford to lose but not by a large margin and this is what we achieved.
"If Argentina wins all their matches, we may only need four points to qualify - everything hangs on the match between Nigeria and Iran."