Skipper Morgan Newman, of Western Province, kicked 10 points on a rain-soaked night and there were three tries to add to his contribution. Bjorn Basson, Howard Noble and Jody Jenneker scored the tries to ensure the South African's 10-6 interval lead was maintained.
"This is a young team that is being groom to be the Springbok team within the next two or three years. I think the talent is there," said 1995 Rugby World Cup winner Williams, who coached the side.
A number of the winning side are expected to come into contention for the Emerging Springboks team that will take on the British & Irish Lions next year. Not only that, many of the players will be challenging for places in the provincial matches against the tourists.
"We are very happy because we won for the second time in a row. It's a great tournament and Romania is a very good side," said Newman.
"All the 26 of us played really well. We will go now back to our union for our domestic competition and, hopefully, some of us will go now to the full Springboks side."
Emerging South Africa squad: Backs: Justin St Jerry (Golden Lions), Sarel Pretorius (Griquas), Isma-eel Dollie (Western Province), Rocco Jansen (Blue Bulls), Morgan Newman (Western Province), Howard Noble (Free State Cheetahs), Bjorn Basson (Griquas), Joey Mongalo (Blue Bulls), Lollo Waka (Leopards), Rudi Vogt (Pumas), Jody Rose (Golden Lions), Richard Lawson (Western Province). Forwards: Janro van Niekerk (Boland Cavaliers), Greg van Jaarsveld (Border Bulldogs), Phillip Lemmer (Free State Cheetahs), Kobus Grobler (Golden Lions), Hendrik Roodt (Blue Bulls), Zolani Mofu (Boland Cavaliers), Hilton Lobberts (Blue Bulls), Devon Raubenheimer (SWD Eagles), Jody Jenneker (Natal Wildebeest), Sangoni Mxoli (Blue Bulls), Jacobie Adriaanse (Western Province), Berend Botha (Blue Bulls), Carel Hoffman (Blue Bulls), Robert Kruger (Leopards).