The Norway striker, who is likely to leave Dortmund next summer, initally failed to double his side's lead following a wonderful strike from Jude Bellingham.
Haaland would have been salivating after great work from Donyell Malen on the left hand side as he robbed the ball from two Besiktas players and squared it to the striker as Ersin Destanoglu advanced.
Yet despite the prospect of an open gaol, the Norway international managed to inexplicably blast the ball high and wide of the empty net.
The Chelsea and Man City target did double the lead after great work from Bellingham, who impressed yet again.
The England international combined incredible power and poise to burst into the box unmarked and collect Thomas Meunier's pass on his chest before firing a volley home.
The former Birmingham City midfielder has become the youngest player ever to score in consecutive Champions League games, surpassing Kylian Mbappé.
Bellingham is currently in the centre of a tug-of-war between a number of Premier League sides, if rumours are to be believed, with this strike doing little to dispel those reports.
Liverpool and Manchester City are said to be interested in the 18-year-old, yet Sport Bild claim Dortmund are unlikely to sell for anything less than €100million (£85m).
The goals proved decisive as the German club got their Champions League campaign off to a winning start.
They ended up 2-1 winners with Javi Montero grabbing a late consolation for Besiktas.