Tuncay Sanli headed Boro ahead early on and Stewart Downing got their second after 83 minutes, but in between Torres struck three times to clinch victory.
"But he has done that so well. He has power and pace, he can kill defenders with his pace.
"He has proved to be a great signing. Last summer we had 10 names we were considering, then it was down to three. But we went for Fernando because he was hungry and had the style to handle the Premier League.
"It is difficult to score 20 goals for anyone in a season, but he has done that well before the end of the campaign. Everything is possible now for him as he progresses in the game here."