Reigning champions South Africa easily saw off Fiji's threat in Wellington with a bonus-point Pool D win.
Having beaten Wales 17-16 in their opener the Springboks moved up a gear against the islanders.
Gurthro Steenkamp and Jaque Fourie scored first-half tries with Francois Steyn, Morne Steyn, Tendai Mtawarira, Danie Rossouw also going over.
The Steyns kicked the rest of the Boks' points with Fiji's first-half penalty coming from Seremaia Bai.
South Africa's win underlined their tag as favourites to win a group in which Wales face Samoa on Sunday in Hamilton.
Fiji began their challenge with an impressive 49-25 win over Namibia, but were unable to repeat their 2007 heroics when they gave eventual winners the Springboks a fright in the quarter-finals.
The contest was effectively out of Fiji's reach by the break.
Centre Francois Steyn kicked a 60-metre penalty, prop Steenkamp powered over on the left and Morne Steyn added the conversion and a penalty before Fourie crossed the line.
Fly-half Morne Steyn put the extra points onto centre Fourie's try with centre Bai's response coming in the 20th minute.
Francois Steyn was next to go over and his namesake reached the try bonus as Fiji's misery continued in the face of Springbok superiority.
Steenkamp's replacement Mtawarira then powered through a splintered defence and lock Rossouw also earned a front-five reward with the final try.
South Africa: Lambie; Ndungane, Fourie, F Steyn, Pietersen; M. Steyn, du Preez; Steenkamp, Smit, J du Plessis, Botha, Rossouw, Brussow, Burger, Spies, Alberts.
Replacements: Hougaard for Ndungane (54), de Jongh for Fourie (70), Pienaar for du Preez (70), Mtawarira for Steenkamp (64), B. du Plessis for Smit (54), Alberts for Botha (40), Muller for Alberts (47).
Fiji: Murimurivalu; Goneva, Lovobalavu, Bai, Nalaga; Luveniyali, Kental; Ma'afu, Koto Koto, Manu, Nakarawa, Lewaravu, Waqaniburotu, Qera, Matadigo.
Replacements: Fatiaki for Bai (74), Talemaitoga for Luveniyali (65), Buatava for Kental (54), Little for Koto Koto (65), Nailago for Manu (71), Talei for Lewaravu (74), Koyamaibole for Matadigo (51).