Worcester made it back-to-back bonus-point Challenge Cup Pool One wins with victory over Bucuresti to keep their quarter-final hopes alive.
Josh Drauninui's 15th minute try earned the Warriors a 7-3 lead, before Jake Abbott made it 12-6 at the break.
Florin Surugiu's converted score gave the hosts a slender lead, before Errie Claassens put Worcester back in control with his first try for the club.
James Currie then crossed at the death to ensure Worcester took five points.
Bucuresti: Vlaicu; Gheara, Makapelu, Dinis, Apostol; Florea, Surugiu; Dobre, Tasca, Badalicescu; Ratiu, Munteanu; Petreanu, Ion, Rus.
Replacements: Capatana, Ursache, Boar, Popirlan, Mitu, Ivan, Fantanaru, Niacsu.
Worcester: Pennell; Arscott, Short, Tuipulotu, Drauniniu; Gray, Arr; Douglas, Fortey, Tomaszczyk; Percival, Gulliver; Betty, Abbott, C Jones.
Replacements: Hayes, Porter, Currie, Lutui, Dacres, Frost, Goode, Classens.
Referee: Alan Falzone (Italy).