Cameroon had to work hard to open its title defence with a win at the African Cup of Nations, and Ghana was the latest team to be upstaged by an underdog.
Cameroon found it difficult to break down Guinea-Bissau until defender Yaya Banana was left unmarked from a corner to head in the opening goal in the 66th minute.
Cameroon’s second goal came straight after when substitute striker Stephane Bahoken got a lucky break to score with his first touch.
The win put Cameroon top of Group F.
Ghana fought back from 1-0 down to lead 2-1 against Benin in the group’s second game in Ismailia, Egypt, on Tuesday.
Ghana’s goals came through the Ayew brothers, Andre and Jordan.
But defender John Boye was given a second yellow card for time wasting and sent off and Benin equalised for a 2-2 draw.