April 27, 1998, Norfolk, Virginia

In the end, the stunt was a stroke of genius for the WWF, showing that the company was willing to do anything in the Monday Night Wars and it was one of the turning points that led to the WWF prevailing and purchasing WCW’s assets just two years later.
Sources:
WWE.com – DX tells all on their invasion of WCW Monday Nitro
SportsKeeda – WWE News: Eric Bischoff says he would have let DX into the building had he known of invasion beforehand