A 74th-minute Leon Bailey strike on Wednesday night helped Aston Villa beat champions Manchester City at Villa Park in a big Premier League clash.
The three points helped Villa leapfrog Manchester City in the Premier League standings and they are now sitting third in the league table.
Villa are five points clear of fifth placed Tottenham at the moment and Nevin stressed that Emery has done a brilliant job to turn the Midlands club around since arriving at the club.
He conceded that he was wrong to judge Aston Villa for their early season defeat against Newcastle and insisted that the Spaniard has built a special team.
The former top-flight star is certain that Villa are now serious contenders to finish in the top four this season.
Nevin said on BBC Radio 5 Live: “Unai Emery is doing an absolutely phenomenal job at Aston Villa.
“How wrong I was after seeing them get thrashed up in Newcastle in the early weeks of the season.
“Emery has got this side playing together, as a unit and as a team.
“The belief and attitude from every single player, there was no fear at any point of this game against Man City, one of the best teams we have seen for many years.
“This is a special team that Emery has put together.
“I don’t think you can bet against them finishing in the top four this year, plenty may think they are just visiting but I think they’ve got what it takes.”
Aston Villa have a big game on Saturday when they host league leaders Arsenal at Villa Park, something which puts Emery up against his former club.