WATCH: Haaland bags perfect hat-trick as Man City burns Forest
Haaland put City 2-0 up within 23 minutes with two close-range finishes at the Etihad Stadium, before making history with a header seven minutes before the break.
His treble – his second in as many games after he fired City to a 4-2 comeback win over Crystal Palace last time out – took him to nine goals in his first five Premier League outings.
City legend Sergio Aguero and former Newcastle United and Coventry City forward Micky Quinn had previously set the benchmark, with eight goals in their first five appearances in the competition.
Indeed, Haaland, with nine, has already scored more goals in five appearances in August than Harry Kane has in 26 (eight).
