The declaration was made Monday morning by Faraday Orumwese, Vice Chancellor of the University of Benin and the returning officer in the election.
The returning officer announced that Mr Lyon polled 352,552 votes to defeat Duoye Diri of the Peoples Democratic Party (PDP) who polled 143, 172 votes.
The total number of registered voters was announced as 922, 562 and the number of accredited voters was put at 517,883.
In the results announced for Ekeremo local government, the number of registered voters was announced as 125,189 while accredited voters were 41,423. In the local government, the APC won by polling 21,489 votes while the PDP polled 18,344 votes.
Mr Lyon also defeated Mr Diri in Nembe by polling 83,041 votes. Mr Diri, on his part, polled 874 in the local government.
In Sagbama, Mr Diri of the PDP polled 60,339 votes to beat Mr Lyon who polled 7831.
The total number of votes cast was put at 505,884; rejected votes were 6,333; and number of valid votes were put at 499,511.
“That Lyon David of APC having satisfied the requirement of the law is hereby declared winner and returned elected,” Mr Orumwese said in his declaration on Monday.