Barcelona coach Gerardo Martino conceded his side had paid for a slow start as Atletico Madrid booked their place in the Champions League semi-finals for the first time in 40 years with a 1-0 win over the Catalans on Wednesday.
Koke scored the only goal of the game after just five minutes to seal a 2-1 aggregate victory for Diego Simeone's men and Atletico could have won by a far more comfortable margin as they also hit the woodwork three times in the opening 20 minutes.
"At the start the game went like Atletico like it, they were playing direct and winning the second balls. It wasn't that we lacked intensity, but we couldn't put four or five passes together," said Martino.
"We expected to have more control of the ball to avoid their pressing, but we didn't manage to do that.
"There was a big difference between the sides in the first 20 minutes, but after that both sides had their chances."
Defeat means Barca have still not managed to beat Atletico in five meetings this season.
A common factor in all those games has been Lionel Messi's inability to make an impact as the Argentine was again well-marshalled by Atletico and kept on the fringes of the game.
However, Martino insisted Barca cannot always depend on his compatriot to come to the rescue.
"We weren't interested in Messi participating as much in the build-up play as normal as we wanted to isolate him for one-on-ones on the right due to the way Atletico defend the space in the middle.
"Ironically, he had two chances coming more into the centre from cross by Dani (Alves) and Neymar, but we don't base everything solely on Leo.
"There is Cesc (Fabregas), Andres (Iniesta), Neymar, the full-backs. When we win, lose or draw we do so as a team."
There was a completely different set of emotions for Simeone as Atletico's incredible turnaround under his tenure continues.
However, he insisted Atletico's inexperience will ensure they remain underdogs in the semi-finals.
"We maintain the same humility. We understand that the other teams have been there far more than Atletico Madrid.
"We are there 40 years later and we believe in what we are doing. We want to continue being competitive as was our intention at the start."
Atletico's victory was even more remarkable as it came without top-scorer Diego Costa and influential midfielder Arda Turan.
Simeone admitted he refused Costa's plea to play despite a hamstring injury to ensure the Spanish international will be fit for the remainder of the season with Atletico also just six games away from their first La Liga title since 1996.
And the Argentine waved away suggestions that progression on the Champions League stage could attract unwanted attention from Europe's biggest clubs looking to prize away a few of Atletico's key assets.
"We envy many other teams from a financial point of view, but from a competitive point of view we envy no one."