Supporters started to gather at the Milburn entrance to St James' Park long before kick-off, and were joined shortly before 2pm by a black and white throng as a series of organised marches converged on the stadium.
The mood was one of defiance as they chanted for Keegan and against club owner Mike Ashley and executive director (football) Dennis Wise.
Many carried placards bearing the message 'No more Geordie cash for Ashley' - a reference to a call for people to boycott Ashley's Sports Direct stores and the club's retail outlets.
Banners included 'Ashley is a Mackem', 'Ashley and Gang out' and a series of 'Wanted' posters, while some protesters wore T-shirts saying 'Ashley and the Wise guy out' and 'Ashley not so Wise, sack the Board'.
Mounted police moved in in an attempt to disperse the gathering crowds, while journalists were also moved on by officers and club stewards, a response which simply caused the mood to darken.
Ironically, the scene came as it emerged that talks between Ashley and Keegan, which caused a sensation on Tyneside, are ongoing.
It is understood the two men are still in discussion over a possible way forward more than a week after the 57-year-old tendered his resignation.