Cameroon defeated Kenya 1-0 when Boris Enow scored the only goal of the game in neutral Kampala, while Ramy Bensebaini netted a first-half spot-kick winner for Algeria against Togo in Lome.
Enow drilled a low free-kick into the goal from just outside the box as Cameroon dominated the contest and did enough to win in the absence of their federation president Samuel Eto’o, who is serving a six-month stadium ban by world governing body FIFA.
The victory takes Cameroon to 10 points from four games in the pool and ensured they cannot finish outside of the top two, which is enough to secure a place at the 24-team finals.
Algeria have a full haul of 12 points from four games after Bensebaini converted a penalty on 18 minutes to give them lead, but they had to weather heavy pressure from their hosts, who created enough chances to get something from the game.
Cameroon and Algeria join the hosts and Burkina Faso as the four teams so far confirmed for the finals.
Zimbabwe moved into a strong position in their pool with a 3-1 win over Namibia in neutral Johannesburg that leaves them on eight points, four ahead of third-placed Kenya with two rounds to play. One of those fixtures is at home to Kenya next month.
Walter Musona scored a brace, one a penalty, to go with a strike from Prince Dube.
Equatorial Guinea are five points clear in second place in their pool after a 2-1 win over Liberia in Monrovia.
Luis Asue had them in front early, but William Gibson equalised for the hosts. Just as it appeared the game would end in a draw, Dorian Hanza netted a 94th-minute winner.
Musa Barrow scored the decisive goal for Gambia in their 1-0 victory over Madagascar, making up for a penalty miss earlier in the game.
Gambia move into second place in their pool, ahead of Comoros on head-to-head record, but having played a game more.
Mozambique moved to the top of their pool with a 3-0 win over Eswatini in Nelspruit, their first goal scored by 40-year-old winger Domingues.
They are five points clear of third-placed Guinea Bissau, who host Mali on Tuesday.