Spain coach Luis Aragones paid tribute to Tunisia after his side fought back from a goal down to win 3-1 and qualify for the last 16 of the World Cup.
"I knew it would be a very complicated and difficult game," he said.
"They caught us on the break in the first half and then shut up at the back and it was tremendously difficult for us to break through.
"After Cesc (Fabregas) took a shot and Raul got the goal, it became much easier to open them up."
Joahar Mnari opened the scoring for Tunisia in the first half and the African side looked set for a shock victory.
But Spain equalised midway through the second half thanks to Raul who scored from close range, before Atletico Madrid's Fernando Torres scored the all-important second and third.
Torres agreed that the Tunisians proved a stiff test for his team-mates.
"It was harder than we expected but it is important to win any way you can," said the Atletico Madrid forward.
"The team showed spirit and did not get downhearted when they were behind.
"As long as the strikers keep scoring we will progress in this tournament."
Raul added: "Regarding my goal, it was very important for the team to get back on terms.
"It calmed us down and it says a lot for the team that we hung on in there and came back."