Caleb Porter's side skipped away to a two-goal lead within seven minutes at the MAPFRE Stadium in Columbus before Gregg Berhalter's Crew outfit pulled one back in the 18th minute but could not overcome the visitors.
Diego Valeri scored the fastest goal in a MLS Cup final when he closed down Crew keeper Steve Clark to slide the ball home after just 27 seconds before Rodney Wallace headed home Lucas Melano's seventh-minute cross despite the ball appearing to go out on the right flank in the lead-up.
Columbus were rocked by the early flourish from the Timbers but managed to respond when Kei Kamara scored on the turn during a goalmouth scramble.
On the hour-mark, the Crew should have gone 3-1 down but somehow the ball managed to stay out when Wallace shot on target with Michael Parkhurst denying the initial shot before Kamara almost turned it into his own net. The ball hit the crossbar and the upright and remarkably still stayed out.
10 minutes later, Fanendo Adi's header looped past Clark before striking the far upright before Clark produced a reaction save to deny Nat Borchers' back post header from point blank range.
At the death, the Crew tried in vain to find an equaliser but could not get past a desperate Timbers defence as the Cascadia club held out for a famous win to bring home their very first MLS trophy.
2015 MLS CUP FINAL