Petkovic acknowledged that Nigeria completely dominated Algeria throughout the match.
Nigeria will face host nation Morocco for a place in the tournament final in a high-profile clash on Wednesday.
Cameroon doubled the advantage just two minutes into the second half after Christian Kofane headed home a cross from Aboubakar Nagida.
Morocco will face the winner of the quarterfinal match between Cameroon’s Indomitable Lions and Bafana Bafana of South Africa for a place in the semifinals of this year’s tournament.
Comoros head coach, Stefano Cusin, stressed that the opening game would provide an opportunity for his side to showcase themselves.
The competition’s overall prize money has been increased from $975,000 to $2.4 million – an increase of almost $1.5 million.
