Joel Piroe, who joined this summer, scored twice, and Georginio Rutter added a third as Daniel Farke’s team displayed the dynamism they hope will get them back into the Premier League at the first attempt.
They achieved victory at The Den for the first time since March 2012, securing bragging rights in what has grown into a heated rivalry between the two clubs.
Piroe, who cost £10.5 million to acquire from Swansea last month, completed a deft move in the 15th minute after Georginio had set him up to score.
On 78 minutes, Dan James tripped over the ball but managed to direct it into the path of the Dutch striker, who had a simple tap-in opportunity to double the lead.
Moments later, when James had picked him out in the box, Georginio made sure to score by slamming the ball high into the goal.
While Leeds climb into 10th in the early season standings, Millwall sit 18th with seven points gained from their opening six games.
While Leeds climb into 10th in the early season standings, Millwall sit 18th with seven points gained from their opening six games.
