Manchester United was held to a 1-1 draw by last-placed Burnley as the Premier League giant dropped out of the top four, while Newcastle secured a lifeline in its survival bid with a 3-1 win against Everton on Tuesday.
Ralf Rangnick's side slipped down to fifth place after Jay Rodriguez canceled out Paul Pogba's opener at Turf Moor.
West Ham moved up to fourth, one point ahead of United, after a 1-0 win against second-bottom Watford at the London Stadium.
But its match was overshadowed by David Moyes' controversial decision to select Kurt Zouma just hours after the French defender was forced to apologize when a video emerged of him kicking and slapping his cat.
With Cristiano Ronaldo left on the bench for 68 minutes, Manchester United was made to pay for not making more of a dominant first half after Pogba put it in front with a thunderous strike from the edge of the area in the 18th minute.
United's troubled season hit another bump in the road when it was dumped out of the FA Cup by Championship side Middlesbrough on penalties earlier Friday.
The lessons from that defeat were not learned as again it had more than enough chances to kill the game before being punished for a slack piece of defending.
Two minutes after the break, Wout Weghorst left Harry Maguire trailing and slipped in Rodriguez, who held off the United captain, to dink the ball beyond David De Gea.
"Again we played an excellent first half. We controlled and dominated the game. We scored the three goals but two were disallowed," Rangnick said.
"In the second half, we were not aggressive enough. A frustrating night for us because we should have won that game comfortably."
Burnley's 11th draw in 20 league games this season was not enough to move them off the foot of the table.
'Big result'
At St. James' Park, Newcastle fell behind to Jamaal Lascelles' own goal in the first half.
But the Magpies had the perfect response as Mason Holgate's own goal sparked a rousing revival.
Ryan Fraser put Newcastle ahead after halftime and Kieran Trippier's superb free kick rounded off the hosts' second successive win.
Mired in the bottom three for most of the season, Newcastle finally has its heads above water as it battles to avoid sinking into the Championship.
Unbeaten in four league games, Newcastle is one place and two points above the relegation zone.
"It's a big result for us. We are in a better place, but football has a way of twisting and turning, so we are not getting ahead of ourselves," Newcastle boss Eddie Howe said.
Everton is now in serious danger and new boss Frank Lampard will have been left in no doubts about the size of the task facing him.
Lampard's first game in charge was a 4-1 win over Brentford in the FA Cup fourth round Saturday.
But the honeymoon ended much quicker than the former Chelsea boss would have liked.
Everton has failed to win its last six league games and sits uncomfortably just one point above Newcastle.
"It was a tough game to have as we have only been together for a week. We need to not let our heads drop. The work starts now," Lampard said.
Meanwhile, Essex police have launched an investigation into Zouma's treatment of his cat and West Ham condemned the incident, but Moyes said he picked him because he was "one of our better players."
Zouma was booed by both West Ham and Watford fans during the match, with Hornets supporters singing "that's how your cat feels" when the 27-year-old went down injured.
An online petition calling on Zouma to be "prosecuted for animal cruelty" had attracted 25,000 signatures by the time the match kicked off.
Zouma is seen in the video dropping and kicking the cat, with laughter can be heard in the background, before he throws a pair of shoes at it.
"He will remain available for selection. The club will sort the other side of it out and I'll look after the football side," Moyes said.
Jarrod Bowen's deflected winner in the 68th minute was the only silver lining on a grim day for the club.