Malawi, making their first African Nations Cup appearance for 26 years and only their second overall, stunned World Cup qualifiers Algeria 3-0 in their opening Group A match on Monday.
Russell Mwafulirwa gave the rank outsiders a 17th-minute lead when he took advantage of slapstick defending and Elvis Kafoteka headed a second before the break in a near-deserted November 11 stadium.
Davi Banda scored early in the second half to complete Malawi's first ever win at the tournament and send them top of Group A, ahead of hosts Angola and Mali who drew 4-4 on Sunday.
Malawi, who took one point from three games on their debut appearance in 1984 when their results included a 3-0 defeat by Algeria, were not expected to do much better this time around with an apparently lightweight squad.
But with nine European-based players in their starting line-up and the game kicking off in mid-afternoon, Algeria struggled in the stifling tropical heat and made life even more difficult for themselves by gifting Malawi the opener.
Goalkeeper Faouzi Chaouchi and defender Madjid Bougherra collided as they tried to clear a pass into the Algeria area and the ball ran to Swedish-based Mwafulirwa who scored into an empty net.
Algeria's best chance came shortly afterwards when Rafik Saifi broke clear of the offside trap but lobbed the ball over.
Malawi increased their lead in the 36th minute when Moses Chavula crossed from the left and Kafoteka headed home.
Three minutes after the break, the dangerous Mwafulirwa drilled a shot against the post but the Algeria defence failed to clear and the ball fell to Banda who scored with a low shot.
Algeria never threatened to emulate Mali, who scored four times in the last 11 minutes to recover from 4-0 down to draw with Angola in the tournament's opening match.