Very difficult to say what will happen.
The votes left to be counted are remote rural areas and a number of countries abroad.
In total just under a million Peruvians who are eligible to vote live abroad. That’s approximately 5% of the electorate. However, turnout abroad is much lower, between 35% and 40%, whereas in Peru itself turnout is 76%.
The countries abroad where votes have been counted have all gone to Fujimori, usually by 2/3 of the votes and only 1/3 for Castillo. In the UK the result was 69% vs 31%. Countries that haven’t declared yet and that could tip the balance include Spain and the US.
Latest, after 95% of the votes have been counted:
PEDRO CASTILLO: 50.167%
KEIKO FUJIMORI: 49.833%