Argentina 50-3 Romania
Tries: Gaitan, Hernandez (2), M Contepomi, N Fernandez Miranda, Bouza (2)
Con: J Fernandez Miranda (4), Quesada (2)
Pens: J Fernandez Miranda
A second-string Argentina rumbled past a poor Romania side in a scrappy encounter in Sydney.
The Pumas outscored Romania seven-tries-to-nil but looked far from convincing in an error-strewn match.
Argentina took their time to warm up and reached the break 24-0 up after a first-half littered with handling mistakes despite plenty of possession from a powerful pack.
As the game wore on and Romania tired, Argentina began to exert their influence, aided by the introduction of first-teamers Gonzalo Quesada and Agustin Pichot.
Argentina meet Ireland on Sunday in a potential Pool A runner-up decider after losing against Australia and beating Namibia.
The Pumas began loosely, with little pattern or control at the Aussie Stadium.
After squandering an early drop-goal, they made their first breakthrough on 10 minutes when lateral-running fly-half Juan Fernandez Miranda popped a crash ball to centre Martin Gaitan, who thundered over from the 22-yard line.
Fernandez Miranda hit the conversion but shortly after made a mess of an easy penalty attempt before his brother Nicolas was wayward with another drop-goal effort.
A period of sloppy rugby was eventually halted when Argentina doubled their try tally on 29 minutes, with Juan Fernandez Miranda's chip-through bouncing kindly for full-back Juan Martin Hernandez, who was able to flop over.
Nicolas Fernandez Miranda scores for Argentina
The Pumas edged further clear with a Juan Fernandez Miranda penalty from wide on the right on 32 minutes.
And just before the interval, Argentina added some gloss to the scoreline with an opportunist try from Manuel Contepomi after Romania, trying to break from their own half, spilled the ball in midfield.
Romania's worries continued immediately after the break when fly-half Ionut Tofan's attempted clearance was charged down by Nicolas Fernandez Miranda, who gathered to cross for Argentina's fourth try.
There was no doubt who was in control but it was from attractive, or accomplished, rugby.
Argentina soon went over for another try, an industrial effort from the pack to set up number eight Pablo Bouza for a pushover try.
Romania finally scored through a Tofan penalty before Bouza grabbed a second try after a five-yard scrum set up from an impudent break by Argentine winger Jose Nunek Piossek.
Fly-half Quesada hit the conversion after coming on as a replacement minutes earlier before Hernandez rounded off a good move with a try on the right.
Quesada struck his second conversion but Argentina were unable to make further inroads and Romania showed a glimmer of defiance with a scrum against the head late on.
Argentina: JM Hernandez; JN Piossek, M Gaitan, M Contepomi, H Senillosa; J Fernandez Miranda, N Fernandez Miranda; R Roncero, M Ledesma, M Scelzo, P Sporleder, P Albacete, S Phelan (capt), M Durand, P Bouza
Replacements: F Mendez, O Hasan, R Alvarez, R Martin, A Pichot, G Quesada, J Orengo
Romania: G Brezoianu; M Vioreanu, V Maftei, R Gontineac (capt), I Teodorescu; I Tofan, L Sirbu; P Toderasc, R Mavrodin, S Florea, S Socol, C Petre, M Tudori, O Tonita, G Chiriac
Replacements: P Ion, C Popescu, V Ghioc, A Petrichei, F Tatu, A Iulian, C Sauan