The 19-12 result meant the Fijians missed out on winning the US tournament for a third consecutive year.
Fiji hit the lead first through a typically aggressive try from Masivesi Dakuwaqa, who forced a turnover before stretching out to score.
However, a few minutes later the Blitz Bokke speedster Cecil Afrika scored under the posts which along with the easy conversion, led to a 7-5 half time score in favour of the South Africans.
