UPDATE 3-Soccer-Barcelona outclass United in one-sided final

* Eto'o and Messi pounce to give Barcelona victory

* United outclassed after bright opening

* Barca end subdued United's record unbeaten run

(Updated with details, quotes)

By Mike Collett

ROME, May 27 (Reuters) - Barcelona deposed Manchester United as European champions with a 2-0 victory forged by a superb display of controlled attacking soccer in the Champions League final on Wednesday.

Cameroon striker Samuel Eto'o struck the opener against the run of play after 10 minutes at the Stadio Olimpico when he cut past Nemanja Vidic with surprising ease and sent a low shot past United goalkeeper Edwin van der Sar at his near post.

Argentina's Lionel Messi added the second with a rare, and perfectly timed header after 70 minutes, sealing Barcelona's third European Cup win after their successes in 1992 and 2006.

Victory also completed a European and domestic treble for Barca in an extraordinary first season for coach Pep Guardiola, who ended Alex Ferguson's dreams of making United the first side to retain the European Cup in the Champions League era.