The Nigerians were unimpressive in the first half in Alexandria CAIRO: Former champion Nigeria became the first team to reach the last 16 at the African Cup of Nations after defender Kenneth Omeruo’s second-half goal delivered a 1-0 win over Guinea on Wednesday. The Nigerians were unimpressive in the first half in Alexandria but lifted their game in the second. Alex Iwobi’s rasping shot was pushed away by Guinea goalkeeper Ibrahim Kone and Ahmed Musa almost set up Odion Ighalo on a counterattack. Omeruo did what the forward had not been able to do when he beat Kone with a glancing header at the near post off Moses Simon’s corner in the 73rd minute. Nigeria, which won the title in 2013, has two wins from two games in Group B. It beat Burundi 1-0 in its first match and now needs a draw from its last fixture against Madagascar to finish top and stay in Alexandria for the last 16. There was more good news for Nigeria when Samuel Kalu came on as a substitute near the end. The midfield player collapsed at a training session the day before the first game, suffering from dehydration, and was hospitalized. Coach Gernot Rohr rested captain John Obi Mikel against Guinea.