The African nation raced into a three-goal in the first half and, though they were made to work in the second period, sealed a crucial victory
Algeria moved to within touching distance of reaching the last-16 of the World Cup for the first time after beating South Korea 4-2 in a six-goal thriller in Porto Alegre.
Vahid Halilhodzic’s men ran riot in the opening 45 minutes as the South Korea defence was found wanting time and again.
Islam Slimani opened the scoring midway through the opening period by lifting the ball over goalkeeper Jung Sung-ryong from a long-range pass, before Rafik Halliche doubled the advantage and Abdelmoumene Djabou made it three.
Son Heung-min stopped the rot by slotting the ball between the legs of Rais M’Bolhi to reduce the deficit just after the interval, but it proved to be brief respite for the 2002 World Cup co-hosts.
Yacine Brahimi appeared to put the result beyond doubt in the 62nd minute, but a Koo Ja-cheol strike 10 minutes later kept the match alive as a contest.
However, Korea were unable to set up a nervy end to the game as Algeria went two points clear of Russia in second place in Group H with one game left to play.
Algeria – a team who failed to score a single goal in South Africa in 2010 – become the first African nation to score four goals in a World Cup fixture.
While South Korea were unchanged from their 1-1 opening draw with Russia, Halilhodzic made five changes to the Algeria side that started the 2-1 defeat to Belgium.