Barcelona star Lionel Messi watched from the sideline as Bayern Munich completed its dismantling of the Spanish side with a 3-0 win on Wednesday, lining up the first all-German Champions League final against Borussia Dortmund.

With its all-time leading scorer out after he aggravated a right hamstring injury, Barcelona failed to seriously threaten Bayern's goal _ much less an epic comeback after its 4-0 first-leg defeat.

Bayern, meanwhile, humbled a team that has been the envy of European football for a second time in only nine days.

“I think it is a terrific performance, it is a little bit of history,” Bayern forward Arjen Robben said. “If we perform like this, against a team who have dominated Europe for the past five years, who have so much quality, it is amazing.”

After the visitors had toyed with Barcelona in the first half, Robben finally opened the scoring in the 49th minute before Barcelona's Gerard Pique added an own goal in the 72nd. Thomas Mueller headed in Bayern's third goal just four minutes later, as Barcelona slumped to its first home loss in European competition since 2009.

Four-time winner Bayern will face Dortmund in the final on May 25 at Wembley Stadium.

Besides Messi, Barcelona was also without four other first-choice players. But the glaring truth is that even with several Spanish internationals on the pitch Bayern, was once again the better side.

And after this tie, it's clear that the power has shifted away from Camp Nou further east.

Pique described it as one of his club's “worst nights,” adding that even Messi wouldn't have made a difference.

“It isn't pleasant living through a situation like this,” Pique said. “In the first half, we really tried but when they scored the first we were left feeling down. We have to congratulate Bayern who were superior.

“The fact that Lionel Messi, the best player in the world, did not play was a factor _ but I do not think his participation tonight would have changed things all that much.”

While fellow Spanish side Real Madrid won 2-0 on Tuesday to almost reverse a 4-1 first-leg loss to Dortmund, Barcelona didn't even come close and definitely didn't bow out of Europe's top-tier competition gracefully.

Instead, its second stinging defeat to the newly-crowned German champions will surely open a period of reflection in the club, despite being on course to win the Spanish league title. The Catalan side has been seriously outclassed for the first time since a trophy-laden era started in 2008 under the guidance of former coach Pep Guardiola, who will take over as Bayern coach next season.

After these performances, Guardiola will have a tough time matching the job Jupp Heynckes has done this season.

“When the draw came out and we were paired with Barcelona, I would never have imagined that we would win 4-0 and then 3-0 at the Camp Nou,” Heynckes said. “Barcelona is a fantastic team. Today it had personnel problems, when Messi plays it is very different. However, we played a game at a very high level for 90 minutes.”

Bayern lost last year's final at home to Chelsea in a penalty shootout. It also reached the 2010 final, but went down 2-0 to Inter Milan.

“I believe any team in the world would have trouble playing us because we are a unified group with clear objectives,” Heynckes said. “We have won the league, are in the (German) Cup final, and in the final of the Champions League after we lost last season due to some very bad luck.”

Cracks had already appeared in Barcelona's reign, which had seen it win the European Cup three times in the last seven years, during the round of 16 with a 2-0 loss at AC Milan, before Messi dug down and scored twice to help secure a 4-0 win.

“He's the worst player for us to lose,” said Barcelona midfielder Xavi Hernandez. “Practically all the passes in the last three quarters of the pitch are for him.”

Since injuring his leg on April 2, Messi's only start had been against Bayern. He had missed three games and come off the bench in two more, including last Saturday's Spanish league game at Athletic Bilbao where he scored one goal and set up another.

Barcelona coach Tito Vilanova said that Messi had felt “something” in his leg in the final minutes of the game in Bilbao, and that he had decided before the match that it wasn't worth exposing Messi to greater injury.

“We trained today but he wasn't comfortable, and we decided that if we were going to risk him it would be at the end,” Vilanova said.

Having failed to complete that last pass in the first 45 minutes, Bayern finally converted just after halftime when Robben received the ball on the right flank, cut back to his left to shake off Adriano, and curled one of his trademark left-footed shots over the outstretched Victor Valdes and into the far side of the net.

Bayern then pressed its advantage and quickly turned a win into humbling of Barcelona.

Pique added to the home side's misery when he kneed Frank Ribery's cross into his own net in an attempt to clear.

Mueller then netted his third goal of the series when Ribery picked him out at the far post to head home his cross over Valdes. (AP)