Manchester United feared that protests against the Glazers would affect their preparations against Liverpool - and they were absolutely right.
It's the first Premier League game being staged at Old Trafford since the news broke that the board had signed up to the European Super League.
Even with that scheme now lying in tatters and with Ed Woodward having resigned, there's no chance the fury is dying down any time soon.
Of course, many United fans have hated the Glazers since day one of their hostile takeover and have made their feelings known through green and gold scarves and chants.
But now, the consensus is growing, the time has come for more direct action.
Ahead of kick-off against Liverpool, with the eyes of the world ready to feast on English football's most famous fixture, 10,000 supporters were expected to descend to demonstrate against the club's owners.
Fans had burned an American flag and some attracted criticism for singing "Joel Glazer is going to die" as well as the familiar chant of "We want Glazers out".
As the videos show, the team bus outside the Lowry Hotel was caught up in the disruption.
At the time of writing, it's not yet clear if kick-off could be delayed.
There have been widespread protests across the UK from fans of all of the 'Big Six' clubs involved in the breakaway plans.
While it took just three days for the European Super League to collapse - largely due to the ire of supporters - that doesn't mean the Glazers, or other owners for that matter, will be forgiven quickly.
United's billionaire owners reversed hundreds of millions of pounds worth of debt into the club, and still take dividends out of it. They are also widely blamed for the Red Devils' recent demise post-2013 and lack of investment.
Indeed, Gary Neville echoed the sentiments of many United fans when he called them "scavengers" who need "booting out of football" in an impassioned rant about the Super League.
Sunday was the chance for thousands of United fans to vent their anger.
(Credit: The Football Terrace)