Raheem Sterling was hailed as one of "the top five players in the world" after the Manchester City star stunned Atalanta with an 11-minute hat-trick.
England ace Sterling scored his first Champions League treble in the second half of City's 5-1 demolition of the Serie A side at the Etihad on Tuesday.
The win kept up City's 100% record in Group C and put them on the verge of qualification for the knockout stages, while Sterling's hat-trick took him to 12 goals for the season - and he also had a hand in City's other two.
Ferdinand was effusive in his praise of a player who already has 55 England caps and 12 international goals at the age of 24, saying Sterling is "impossible" to play against and getting better all the time.
And the former Manchester United defender said he rates Sterling among the world's biggest football superstars.
"We are running out of great words to say about him," Ferdinand said on BT Sport.
"He is a young English player who has played a lot of games. He is still improving and adding more to his game.
"He is in the top five players in the world. I don't care who you mention.
"The effect he is having, the goals he is scoring, it is impossible to keep him out."
Ferdinand also credited Pep Guardiola, who has helped Sterling develop from the pacey winger City signed from Liverpool four years ago to the much more complete forward now terrorising defences in the Premier League and in Europe.
"He has a striker's nose to get into certain areas," Ferdinand said of Sterling.
"Sometimes you are blessed to get a manager to learn from. Pep Guardiola coming at the time he did, to coach this young player with immense potential."
