The African side claimed a 4-2 win in Porto Alegre to boost their hopes of making it through to the knockout stages.
"We played an almost perfect first period," BBC Sport quotes him as saying.
"We played very well, very effectively and then it went down a little bit - maybe it was psychological, maybe it was physical - we will have to talk about this.
"But I think that this was a real feat this afternoon and I would like to congratulate my players."
Victory for Algeria was their first in the World Cup since 1982.