Argentina coach Lionel Scaloni said a dramatic 3-2 win over Cape Verde after extra-time to reach the last 16 of the World Cup had left a bruising impact on the defending champions.
In oppressive Miami heat, Scaloni's side were pushed all the way by the African archipelago of just over 500,000 people.
Lionel Messi's 20th World Cup goal and seventh of this tournament gave Argentina the perfect start.
But the Blue Sharks refused to give up on a remarkable first appearance at the World Cup.
Deroy Duarte's strike on the hour mark forced the game to extra-time.
Even when Lisandro Martinez restored La Albiceleste's lead, a stunning strike from Sidny Lopes Cabral's brought Cape Verde level again.
Argentina finally edged through to a last 16 meeting with Egypt on Tuesday when Diney Borges turned into his own net under pressure from Cristian Romero.
"Of the 100, this one has surely left the biggest mark on me as a coach," said Scaloni after his 100th match in charge of his country.
"It would have been crazy to have lost."
Argentina had appeared to have landed in a kind quarter of the draw.
If they progress past Egypt in Atlanta, a quarter-final against Switzerland, Colombia or Ghana awaits.
But Scaloni said Cape Verde had shown his side can take nothing for granted.
"I want to congratulate the opponent. When people say there are no easy games, today they proved they are a great team," added Scaloni.
"I'm taking away the contribution from everyone. We finished very tired, but they gave it their all."
kca/rcw
