Senegal came from behind to beat Ghana 2-1 with a stoppage-time winner on Monday at the African Nations Cup in Mongomo, Equatorial Guinea.
Moussa Sow stole victory right at the end after Senegal had gone behind early and then dominated after that.
Andre Ayew stroked home a 14th-minute penalty for Ghana after Christian Atsu was fouled by Senegal goalkeeper Bouna Coundoul.
But Senegal produced long periods of pressure before Mame Diouf equalised with a second-half header after his initial effort bounced back off the bar.
Substitute Sow then scored in the 93rd minute -- after a string of chances -- to give Senegal a huge boost in Group C.
Ghana skipper Asamoah Gyan had to watch from the dugout after the striker was diagnosed with mild malaria over the weekend and spent a night in hospital.
Tournament favourites Algeria came from behind to beat South Africa 3-1, avoiding a big upset at the start of their campaign.
Faouzi Ghoulam and Islam Slimani scored to turn things around for Africa's top team after they fell behind and survived a missed penalty by South Africa.
Bafana Bafana led through Thuso Phala's 51st-minute goal and won a penalty two minutes later. However, Tokelo Rantie's spot kick rebounded off the crossbar.
That miss appeared to lift the Algerians, who equalised through an own-goal in the 67th minute when South Africa's Thulani Hlatshwayo misdirected a looping header over his own goalkeeper.
Algeria then found their game late. Ghoulam slipped his marker and smashed in a powerful shot, and Slimani made certain of victory at Mongomo Stadium, taking Algeria top of Group C.