RIO DE JANEIRO, Oct 20 — A presidential runoff between Brazil’s incumbent leader Luiz Inacio Lula da Silva and his right-wing challenger Flavio Bolsonaro will decide the fate of Latin America’s largest democracy on Sunday.

Lula, on the cusp of 81 and seeking a fourth non-consecutive term, is facing stiff competition from the 45-year-old senator, who is the son of jailed ex-leader Jair Bolsonaro.

Flavio Bolsonaro defied expectations by nabbing 47 per cent of the first-round vote over Lula’s 45 per cent in early October.

The runoff victor will either preserve the vast country of 214 million people as a left-wing stronghold in Latin America, or usher it into the ranks of right-wing administrations loyal to US President Donald Trump.