The Dutchman released a perfect left-footed effort past Victor Valdes, before an own goal from Gerard Pique and Thomas Muller's strike added insult to injury for the hosts as they crashed out 7-0 on aggregate.
Dealt a severe blow in the build-up to the semifinal with the news that Lionel Messi would not be available from the start, Barcelona nevertheless started positively in its quest to overturn a daunting four-goal deficit and down Bayern. Both teams poured forward in a frenetic first 20 minutes to the encounter, but the energy was not matched by precision in front of goal and there were few clear chances to show for an entertaining beginning.
Barca in particular suffered against a Bayern defense that was organized and committed around the box, and was forced to try its luck from deep. This almost paid off midway through the first half. Pedro let loose with a bomb 35 yards out, and it was well parried behind by Manuel Neuer to save an opener. It was also the Catalan side that enjoyed the best opportunity of the opening 45 minutes.
Enjoying a rare moment of space and time on the ball, Dani Alves whipped a cross into the box that found Cesc Fabregas. The ex-Arsenal man did well to chest down to Xavi, who found himself free, but the midfielder uncharacteristically lost his cool and fired his volley well over the crossbar.
Despite these isolated moments of pressure, Die Roten coped well with the hosts' advances and always looked dangerous breaking from their own half.Robben and Franck Ribery in particular stood out with all-action performances, stretching the Barca backline albeit without creating too many clear openings before heading in for the interval.
Just three minutes after play recommenced, the game was over as a contest. David Alaba from deep on the left showed terrific vision and matched it in the execution as he changed the direction of play, finding an unmarked Robben on the other side of the pitch. The Dutchman still had work to do, but was unstoppable as he cut back past the challenge of Adriano and fired left-footed into the corner, leaving Victor Valdes no chance between the posts.
The Catalan giants now trailed by five goals, and there appeared to be no hope left of a miracle comeback.
The Blaugrana did not give up after that fatal blow and kept pushing towards goal, but there was no joy for the likes of David Villa as they were suffocated in the final third. Indeed, Bayern was the team that continued to enjoy the best opportunities; Robben side-footed wide of the post with the goal in full view, after a storming run down the left from Ribery had spilt open the Liga leaders.
Messi remained on the sidelines throughout the 90 minutes, unused as Tito Vilanova recognized that the game was beyond the reach of his charges. Further confirmation was provided by the hapless Pique who sliced a cross into his own net with 18 minutes to go.
A convincing defeat soon turned into a humiliation when Muller rose to head in the third, putting the Bayern faithful in full voice as the club marched into its third Champions League final in four years.
The Bavarians' dominant 5-0 victory tees up a first-ever all-German final in Europe's premier club competition, as they prepare to face compatriots Borussia Dortmund in the showpiece. The match is scheduled to take place on May 25 in Wembley.