By Fernando Kallas

BARCELONA (Reuters) -Barcelona's dreams of a Champions League, Copa del Rey and LaLiga treble have vanished after Inter Milan roared back from the brink of elimination to grab a phenomenal 7-6 aggregate win and end the Spaniards' European campaign in the semi-final.

Another show of attacking genius by teenager Lamine Yamal and midfielder Pedri had put Hansi Flick's side within touching distance of their first Champions League final in a decade - before they succumbed to the same defensive flaws they have been getting away with for most of the season.

Barcelona are an attacking juggernaut with 163 goals in 56 games this season: 43 of those in 14 Champions League games.

But they have also been playing with fire at the back, conceding 24 goals in Europe's top-flight competition including four to Benfica, three to Borussia Dortmund and seven to Inter in the semi-final games. 

Barca's thrilling season has included eight fightback wins in all competitions, including against Atletico Madrid, Benfica, Celta Vigo and a couple against bitter rivals Real Madrid. 

But defeat in Milan showed they have to add some defensive steel to their swashbuckling attack. 

After conceding 16 goals in their last seven matches, Barca's young squad has learned a painful lesson against a veteran Inter side chasing a fourth Champions League title and their first in 15 years after losing to Manchester City in the final two years ago.

Over both games, Inter scored seven goals in only 10 shots on target - ruthlessly illustrating Barcelona's vulnerability.

The Italians withstood a storm thanks to their fantastic goalkeeper Yann Sommer who made 14 saves over both legs of the semi-final. Barca lost Germany keeper Marc-Andre ter Stegen early in the season and resorted to veteran Wojciech Szczesny, who came out from retirement but could not make the necessary impact in two close games in Barcelona and Milan.

LALIGA NOW THE PRIORITY

The five-times European winners cannot spend long licking their wounds: they must quickly turn their attention to LaLiga, where they top the table and on Sunday host rivals Real Madrid, who trail them by four points with four games to go.

Unbeaten domestically since late December, Barcelona will try to grab a fourth consecutive victory over Real this season and a second in less than a month after a win in extra time that earned them the Copa del Rey title a few days ago.

"It's very cruel. It's true that the team gave everything and deserved to be in the final, but we're young and we have to learn from this and next year we'll give even more of a fight," Pedri told reporters on Tuesday.

"Now we're hurt, but we have to focus on Real Madrid because on Sunday the league is at stake for us."

(Reporting by Fernando Kallas; Editing by Andrew Cawthorne)