It was not a good Sunday for two of East Africa's sides with Tanzania and Kenya both losing their first Africa Cup of Nations group games..
Both countries are making rare appearances at the finals, which this year are taking place in Egypt.
The BBC's John Bennet says Algeria played with good intensity, a positive approach and plenty of attacking ideas.
In Sunday's other match, Morocco beat Namibia 1-0 following a late own goal.
Monday sees Ivory Coast taking on South Africa, Tunisia playing Angola and Mali facing neighbours Mauritania.