The only goal of the game was scored by Kano Pillars’ Rabiu Ali in the first half.
The home-based Eagles had eliminated Benin in the 2018 Africa Nations Championship (CHAN) qualifiers following a 2-1 aggregate win.
The Nigerians will now meet the winners of the second semi-final between Ghana and Niger Republic in Sunday’s final.
Both teams in Thursday’s tie were evenly matched in the first few minutes but it was Benin that went close through Bah-Yere Mamah whose low cross from the left was blocked.
But it was the home-based Eagles who took the lead thanks to Ali in the11th minute after finishing off a brilliant pass from Anthony Okpotu.
In the 16th minute, Benin’s Charbel Gomez almost pounced on a back pass by a Nigerian defender but Ikechukwu Ezenwa was quick to come off his line to clear the danger.
Three minutes later, Okpotu almost doubled Nigeria’s lead after a pass from Peter Eneji but his goal-bound shot was blocked.
Benin were almost made to pay for sloppy play in their defensive area as Okpotu pounced but his pass to Eneji was intercepted.
In the 33rd minute, Benin were reduced to 10 men as Marceline Koukpo was sent off for a dive.
Goal scorer Ali took a pop at goal close to the edge of the Beninoise 18 but it took a slight deflection before the keeper saved it.
Six minutes into the second half, Benin had a big chance to equalise only for Jules Elegbede to fluff his lines from close range.
In the 63rd minute Eneji almost drove his corner into the net but the Beninoise keeper quickly palmed the effort over the bar.
Eneji should have scored Nigeria’s second goal on 73 minutes after he was played through on goal by Okpotu but his effort was saved by the Benin keeper.
Aremu had a big chance to kill off the tie on 81 minutes after connecting brilliantly with Okpotu’s header but the keeper parried away for a corner.
From the resultant corner Okpotu’s effort was cleared off the line by a Benin defender.
With four minutes left Okechukwu Gabriel connected with Okpotu’s well place cross only to see his effort cleared off the line.
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