Mike Ashley was at St James's Park to see Newcastle United suffer a fourth home league defeat.
Leicester City won 2-0 this afternoon thanks to goals from Jamie Vardy and Harry Maguire.
Newcastle remain third-bottom of the Premier League with two points from seven games.
And the result means that Rafa Benitez's side have made the worst start to a home campaign in the club's history.
There were protests against Ashley, making his first appearance at the stadium in more than a year, before and during the game, which had kicked off amid reports that Peter Kenyon was interested in a takeover.
England manager Gareth Southgate was also at St James's Park.
United were left to rue two good first-half chances and referee Simon Hooper's failure to award a penalty against Harry Maguire for fouling Ayoze Perez.
Leicester started well, and Martin Dubravka dnied Pereira, while Wilfred Ndidi headed over from a corner.
The best opportunity of the half was created by Perez with a clever ball for Joselu, who took a touch and gave Maguire time to challenge him before he shot. Mohamed Diame also headed wide from a Christian Atsu cross.
At the other end of the pitch, Dubravka stopped a downward header from Maguire.
Leicester's breakthrough came in the 30th minute when DeAndre Yedlin handled the ball in the box. Vardy stepped up and squeezed the ball between Dubravka and his right-hand post to open the scoring.
Jonjo Shelvey won the ball in midfield and tried to lob Kasper Schmeichel from his own half, but the goalkeeper backpeddled and caught his audacious effort.
Hooper waved away a penalty appeal early in the second half after Maguire blocked and brought down Perez.
Benitez withdrew Ritchie and sent on Jacob Murphy – the decision was booed by some fans – and Yoshinori Muto replaced Perez.
The mood inside St James's Park darkened in the 73rd minute when Maguire headed in a corner from James Maddison.
And there was no way back for Newcastle, who are facing yet another grim relegation battle after another summer of under-investment from Ashley.
NEWCASTLE UNITED: Dubravka; Yedlin (Manquillo, 80), Lascelles, Clark, Kenedy; Ritchie (Murphy, 65), Diame, Shelvey, Atsu; Perez (Muto, 69), Joselu. Subs not used: Darlow, Schar, Hayden, S Longstaff.
LEICESTER CITY: Schmeichel; Amartey, Morgan, Maguire, Chilwell; Ndidi, Mendy; Pereira, Iheanacho, Maddison (Iborra, 85); Vardy (Albrighton, 74). Subs not used: Ward, Evans, Okazaki, Fuchs, Ghezzal.
Goals: Vardy 30 (pen), Maguire 73
Referee: Simon Hooper (Wiltshire)