Chad shocked Egypt 1-0 and Algeria came from two goals down to draw 2-2 with Tanzania, Saturday in African 2018 World Cup first-leg qualifiers.
Congo Brazzaville won 4-3 in Ethiopia and Botswana used home advantage to beat Mali 2-1 in a game that completed the 20 first-leg fixtures in the second round of qualifying for Russia.
The Chadians triumphed in N’Djamena two months after suffering a 5-1 Africa Cup of Nations drubbing from the Egyptians at the same ground.
Tunisia-based captain Ezechiel N’Douassel won the match with a flying header past Ahmed El Shenaway on 73 minutes at Stade Idriss Mahamat Ouya.
Forced to defend for much of the opening half against twice World Cup qualifiers Egypt, the home side took control after the break and the goal rewarded constant pressure.
The return match is scheduled for Tuesday at the Borg El Arab Stadium on the outskirts of Mediterranean city Alexandria.
Islam Slimani struck twice within four minutes midway through the second half for four-time qualifiers Algeria, who are 109 places above Tanzania on the world rankings.
It was the second dramatic comeback in as many days in East Africa by a highly-ranked visiting team with Senegal coming from two goals down to draw 2-2 in Madagascar.
Lacking injured wingers Sofiane Feghouli and Yacine Brahimi, Algeria fell behind to a first-half Elias Maguri goal at the Benjamin Mkapa National Stadium.
Mbwana Samatta, a key figure for 2015 Caf Champions League winners TP Mazembe of the Democratic Republic of Congo, doubled the Taifa Stars’ lead on 55 minutes in Dar es Salaam.
But Slimani from Lisbon outfit Sporting halved the deficit on 72 minutes and struck again soon after to let the Desert Foxes off the hook.
A goal feast at Addis Ababa Stadium saw Ethiopia take the lead and then fall 4-1 behind before scoring twice in the closing stages.
Getaneh Gibeto put the hosts ahead, Thievy Bifouma levelled before half-time and Fabrice Nguessi, Delvin Ndinga and Hardy Binguila scored second-half goals for the visitors.
Dawit Fekadu and Shimelis Bekele scored in a hectic climax to leave Ethiopia needing at least two goals in Brazzaville to survive.
Botswana raced into a two-goal lead over Mali at Francistown Stadium in the north-eastern city through Tapiwa Gadibolae and Joel Mogorosi.
But Samba Sow reduced arrears 11 minutes into the second half and Mali remain favourites to win the tie.
Bundesliga star Pierre-Emerick Aubameyang converted his penalty shootout kick as Gabon became the first team to reach the third round of African 2018 World Cup qualifying.
Gabon beat Mozambique 4-3 on penalties following extra time in Libreville after Gabon won 1-0 to level the second-round tie at 1-1 on aggregate.