Ismaila Sarr scored one goal and laid on another as defending champions Senegal beat Cameroon 3-1 on Friday and booked their place in the round of 16 at the Africa Cup of Nations, leaving their opponents in some peril.

Sarr opened the scoring in the first half of the Group C clash in Yamoussoukro after a mistake by Manchester United goalkeeper Andre Onana, who was playing his first game of the tournament after a late arrival in the Ivory Coast.

Habib Diallo added the second goal from Sarr’s cross before Jean-Charles Castelletto scored a late consolation for Cameroon. Sadio Mane completed the scoring for Senegal in injury time.

The Lions of Teranga advance to the knockout rounds with a final group game against Guinea to spare. Cameroon must play Gambia in their last match. Both of those are on Tuesday.

Senegal head the pool with six points from their two games, while Cameroon and Guinea have a point each and Gambia are yet to break their duck. The latter two sides meet at the same venue later on Friday.

Cameroon barely tested Senegal keeper Edouard Mendy until the final 10 minutes when they could have earned a point after a limp performance that followed a 1-1 draw with Guinea in their opener -- alarming form for coach Rigobert Song.

He selected Onana after the keeper missed the Guinea game in order to play for Manchester United against Tottenham Hotspur in the Premier League, and will be frustrated by the manner of the first goal conceded.

Sarr netted on 16 minutes after Onana attempted to punch clear a cross but did not get the height or distance he needed and the ball fell to the winger, whose deflected shot went into the bottom corner.

Sarr then turned provider when he was left in acres of space on the right-hand side of the box and his low cross was turned home from four yards by Diallo.

That goal seemed to spark Cameroon into life and they found a way back into the contest with a goal from a corner as Castelletto headed in Olivier Ntcham’s cross.

It should have been 2-2 following a horrific miss at the back post from Georges-Kevin Nkoudou, who headed wide with the goalmouth gaping.

Senegal went up the other end and sealed the three points when Mane netted their third goal.