There were disturbances among the home fans at the London Stadium where West Ham lost 3-0 against Burnley.
Ashley Barnes fired the visitors ahead on 66 minutes, prompting a couple of supporters to run onto the pitch, with Irons captain Mark Noble involved in a confrontation before stewards intervened.
Burnley doubled their lead on 70 minutes through Chris Wood's close-range finish, which again sparked an angry reaction as chants of "sack the board" rang out before another fan got onto the pitch and took out a corner flag.
Substitute Wood added a third on 81 minutes following a fumble by recalled goalkeeper Joe Hart and owners David Gold and David Sullivan are understood to have left their seats for their own safety to complete another forgettable afternoon for West Ham, who slip closer to the bottom three.
Bottom club West Brom took an early lead against Leicester before eventually losing 4-1 at The Hawthorns.
The Baggies, on the back of six straight defeats, went ahead on eight minutes through Salomon Rondon but Leicester equalised on 21 minutes after a breakaway goal from Jamie Vardy.
Riyad Mahrez put Leicester in front on 62 minutes, with substitute Kelechi Iheanacho heading in a late third and Vicente Iborra adding a fourth from a corner in stoppage time.
Newcastle dispatched Southampton 3-0 at St James' Park to move away from the drop zone.
Kenedy fired the hosts ahead inside two minutes and then grabbed his second on 29 minutes following a swift counter-attack from a Southampton corner.
Matt Ritchie made it 3-0 just before the hour to lift Newcastle to 13th place while Southampton remain 17th, just a point outside the relegation zone with rivals Crystal Palace and Stoke holding a game in hand.
Everton ended Brighton's recent good run with a 2-0 win at Goodison Park.
Gaetan Bong's own goal broke the deadlock on the hour before Turkey forward Cenk Tosun scored his first home goal to wrap up the points with 15 minutes left.
Brighton finished the match with 10 men after midfielder Anthony Knockaert was dismissed for a high challenge on Leighton Baines. Everton striker Wayne Rooney then saw a late penalty saved.
Swansea also had a player sent off as they battled to a goalless draw at Huddersfield.
Forward Jordan Ayew was shown a red card after just 11 minutes for a high tackle on Jonathan Hogg.
Huddersfield, though, could not make their advantage count and remain in 15th.