The Norwegian took just 14 matches in the English top flight to reach the 20-goal landmark, smashing the previous record of 21 set by Kevin Phillips.
Phillips was ahead of Fernando Torres (27), Alan Shearer (29) and Sergio Aguero (30) who complete the top five.
Our No.9 completed his fourth hat-trick of the season against Wolves at the weekend having already fired three hat-tricks against Crystal Palace, Nottingham Forest and Manchester United.
He has also already scored more goals than the winners of last season's Golden Boot - Son Heung-min and Mo Salah - who both bagged 23 goals.
Across all competitions, the 22-year-old now has 31 goals in just 26 appearances for City since arriving in the summer.
With 18 league matches as well as matches in the Champions League and FA Cup still to come this season, he will be eyeing further goals in the coming weeks and months.
Click on the video above to see all of his 25 Premier League goals to date...