Rauluni, who led Fiji to the quarter-finals of the 2007 Rugby World Cup, will be supported by the dynamic Tongan loose-forward Nili Latu as vice-captain.
MacDonald powered his way over to score in the corner on 46 minutes but Tonga responded with the help of an incisive break from skipper Nili Latu which led to Joseph Vaka scoring his first try for his country.