The Villans leapfrogged Tottenham into the Premier League's top-four with a 2-1 comeback victory over the north Londoners on Sunday.
It comes after Emery dragged Villa from a relegation battle in October to the Europa Conference League in May last season.
Few can doubt the Spaniard's transformative effect at Villa Park - but his first stint in the English top-flight was not such a roaring success.
Emery had the unenviable task of replacing long-term Gunners manager Arsene Wenger in 2018.
His time at the Emirates grew increasingly toxic before Arsenal decided to sack him after 18 months in charge.
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Despite Mikel Arteta's growing success in the Gunners hot seat, Manchester United legend Ferdinand believes Emery was mistreated in north London.
"Unai Emery is doing madness," Ferdinand told the FIVE podcast.
"Arsenal disrespected his whole thing."
Emery, who has won the Europa League four times as a manager, attempted to manage the expectations of a galvanised fan base after the win at Spurs.
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The 52-year-old said: "Of course we can get confidence when we are winning matches like here at Tottenham, but still in my mind, it is 38 matches that we have to be consistent.
"We have to try to get each opportunity with three points and try to get a good position in the table.
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"We are in (the top four) now, but we are not a contender.
"There are seven contenders more than us to be in the top seven, to be in the top four but while we are there, we are going to try to keep (there)."