Cameroon captain Vincent Aboubakar scored his fifth goal of the Africa Cup of Nations and his already-qualified side were joined by Burkina Faso on Monday in the second round.
The Saudi Arabia-based forward, who turns 30 on Saturday, put Cameroon ahead and substitute Garry Rodrigues equalised for Cape Verde after half-time in a 1-1 draw in Yaounde.
Cyrille Bayala put Burkina Faso in front and Getaneh Kebede levelled for Ethiopia from a penalty in Bafoussam in another 1-1 draw that was enough to take the west Africans through.
Cameroon topped the final group table with seven points. Burkina Faso edged Cape Verde on head-to-head records for second place after both accumulated four points. Ethiopia were eliminated with just one point.
While Cameroon and Burkina Faso are assured of last-16 places, Cape Verde must wait to see if they go through as one of the best four third-placed teams from the six groups.
Cameroon will remain in Yaounde to play a third-placed team on January 24, a day after Burkina Faso meet the Group C runners-up in Limbe.
Should Cape Verde survive, they will play the winners of Group B or Group C in Bafoussam or Yaounde on January 25.
"We won the group, which was our goal, although we wanted to win all our matches. We will continue to play here in Olembe," said Cameroon coach Toni Conceicao.
"We had many chances. The Cameroonian team was not brilliant but still played a good game. We can do better, but if we take an overall reading, we were superior to our opponents in the group."
Aboubakar is the first Cameroonian to score in all three group matches at a Cup of Nations since Samuel Eto'o achieved the feat with five goals at the 2008 finals in Ghana.
Ndaye Mulamba holds the record for the most goals by an individual in the flagship African tournament with nine for Zaire (now the Democratic Republic of Congo) in Egypt 48 years ago.
Aboubakar has a clear lead in the Golden Boot competition with his closest rivals, compatriot Karl Toko-Ekambi, Tunisian Wahbi Khazri, Malian Ibrahima Kone and Malawian Frank Mhango, scoring two each.
In Yaounde, Cameroon broke the deadlock on 39 minutes in a cagey opening half dominated by the two defences.
A free-kick from the Indomitable Lions was partially cleared and Aboubakar rifled a low, left-foot shot through a crowd of players and past goalkeeper Josimar 'Vozinha' Dias into the corner of the net.
Cape Verde reacted to falling behind by becoming more adventurous and troubled the Cameroon rearguard several times before half-time without managing an equaliser.
The island nation introduced Rodrigues for the second half and he equalised within eight minutes through an exquisite back-heel off a low cross that beat goalkeeper Andre Onana.
Aboubakar should have put Cameroon ahead again midway through the second half but blazed over when the ball ran loose inside the box.
In Bafoussam, a city 300 kilometres (185 miles) north west of Yaounde, Burkina Faso went ahead on 25 minutes through Bayala.
After a superb long pass from the centre circle by Adama Guira, Bayala outmuscled two Ethiopian defenders and chipped the ball over advancing goalkeeper Teklemariam Shanko and into the net.
But instead of building their lead, the Burkinabe Stallions conceded on 52 minutes when Ethiopia captain Kebede levelled from a penalty awarded after a VAR review.
Burkina Faso welcomed back captain Bertrand Traore, the Aston Villa forward, after his recovery from Covid-19, but a positive test ruled out goalkeeper Herve Koffi.