The high-tension cable fell on a crowded shack showing the Europa League quarter-final against Anderlecht in the southern city of Calabar, the BBC reported.
The survivor said amid sobs: "It happened during the match between Manchester United and Anderlecht".
"Until this morning we have about seven persons dead, we have 10 that have been admitted to hospital and another one in intensive care".
Local Ukeme Joseph said he believed at least 20 people had died after the wire collapsed onto the Calabar viewing centre.
"It was a disgusting sight to behold".
"At this point in time, it is sad to know that the victims lost their lives at a viewing centre where they usually converge, at their leisure time to watch their matches", Ayade said.
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"When I turned back to go inside the viewing center, I saw a cable coming down on the center and this electrocuted the viewers in the hall. This world is vain".
While commiserating with the families of the victims of the tragedy, the governor promised that the state government will look into the likely cause of the incident with a view to preventing a reccurence.
According to a statement by his Senior Special Assistant on Media and Publicity, Malam Garba Shehu, Buhari prayed that God grants the souls of the departed eternal rest and comfort all who mourned their irreparable loss.
United netted an extra time victor through Marcus Rashford, in between scoring two disallowed goals.
Nigeria's President Muhammadu Buhari said he was "shocked and saddened" by the deaths.