Senegal thwarted, South Africa beaten
South Africa were another team to suffer a shock home defeat, losing 2-1 to Cape Verde for the second time in five days, this time in Indian Ocean city Durban.
Garry Rodrigues scored twice in the second half, from a free-kick and a shot outside the box, before substitute Andile Jali snatched a late consolation goal.
Defeat dropped the South Africans to the bottom of Group D, which is headed by Burkina Faso after a dramatic 2-2 draw with Senegal in Ouagadougou.
Bertrand Traore gave the Burkinabe an early lead only for a goal in each half from Ismaila Sarr and Liverpool star Sadio Mane to turn the tide.
But substitute Senegal goalkeeper Pape N’Diaye conceded an own goal in the final minute of regular time to keep Burkina Faso on top of a tight table.
They and Cape Verde have six points, Senegal five and South Africa four with two matchdays remaining.
Tunisia retained a three-point lead over the Democratic Republic of Congo in Group A after coming from two goals behind in Kinshasa to salvage a 2-2 draw.
Goals from captain Chancel Mbemba and Paul Jose Mpoku had put the Leopards in control soon after half-time, but they fell apart in the closing stages.
Wilfred Moke conceded an own goal and Anice Bardi levelled two minutes later.
Tunisia have 10 points, DR Congo seven and out-of-contention Guinea and Libya three.
Captain Kennedy Mweene saved a Riyad Mahrez penalty as second-place Zambia beat Algeria 1-0 in Constantine to close the gap behind Group B leaders Nigeria to three points.
Patson Daka, a key figure in the Zambian 2017 African U-20 Cup of Nations-winning team, scored the only goal midway through the second half.
World Cup Africa zone state of play
Contenders and eliminated teams after matchday 4 of World Cup qualifying in Africa:
Contenders: Tunisia, Democratic Republic of Congo
Eliminated: Guinea, Libya
Contenders: Nigeria, Zambia
Eliminated: Cameroon, Algeria
Contenders: Ivory Coast, Morocco, Gabon, Mali
Contenders: Burkina Faso, Cape Verde, Senegal, South Africa
Contenders: Egypt, Uganda, Ghana
Eliminated: Congo Brazzaville
Note: group winners qualify for 2018 World Cup in Russia