Aleksandar Prijovic kicked things off in the 10th minute, with six further goals coming before the 33rd minute, as Shinji Kagawa added two, Nuri Sahin another, Prijovic a second for himself and Legia before Ousmane Dembele and Marco Reus closed out a frantic 23-minute blitz.
It marked the first time a Champions League game had featured five goals in the opening 25 minutes and the first to involve seven goals before half-time.
Dortmund also tied one of their rivals Champions League records, with five of their own matching Bayern Munich’s haul against Porto in the quarter-final second leg in April, 2015.
Dortmund went on to win 8-4 to break yet another record with their ninth goal against the Polish outfit across both group games, while the 12 goals surpassed Monaco’s 8-3 win over Deportivo 13 years ago as the highest-scoring match in the European competition.
Dortmund have already qualified for the Champions League knockout stage, leading Group F, with Legia Warsaw’s sole point thus far this season coming in a shock 2-2 draw with Real Madrid.
