Chelsea failed to make the most of their numerical advantage as they were held to a 2-2 draw by Arsenal at Stamford Bridge in a thrilling London derby that included a late goal from either side.
Much of the pre-match focus was on the two managers, with Frank Lampard beginning to come in for a bit of criticism after a difficult run, while Mikel Arteta has been accused of doing little to improve Arsenal's fortunes since coming in.
And there were plenty of hints as to why the sides are out of form, with the two sets of defences failing to inspire a great deal of confidence.
Manchester City avoided dropping points, however, with a substitute sparing their blushes in a 1-0 win at Sheffield United, while there was plenty of drama at the bottom of the table.
DAVID LUIZ SEES RED BUT ARSENAL CLING ON
It was an unhappy return to Stamford Bridge for former Chelsea defender David Luiz, who was given a frosty reception and then sent off for a cynical foul that led to a penalty.
From that spot-kick, Jorginho opened the scoring in the 28th minute, suggesting Chelsea were set to cruise.
But a wonderful solo effort from Gabriel Martinelli restored parity just after the hour, leaving Lampard looking a little nervous.
Chelsea retook the lead with what they thought was a winner from Cesar Azpilicueta, the captain turning in a left-wing cross.
But Hector Bellerin's well-placed left-footed effort from the edge of the box found the bottom-left corner and secured the Gunners a share of the spoils, a commendable achievement given their disadvantage. The draw moves Arsenal up to 10th, while Chelsea go six points clear of fifth-placed Manchester United.
AGUERO THE DIFFERENCE FOR CITY
City handed Aymeric Laporte his first appearance since August at Bramall Lane, the Frenchman having recovered from a serious knee injury.
But he was given some rough treatment by the Blades – with Muhamed Besic catching him with a heavy challenge early on.
City did enough in the first half to take the lead, but Dean Henderson was in excellent form between the United posts, making several impressive saves and keeping out Gabriel Jesus' penalty.
But the visitors' persistence paid off. Sergio Aguero came off the bench to get the winner 17 minutes from time, finishing clinically after a glorious pass from Kevin De Bruyne.
That moves them six clear of Leicester City in third, though the 13-point gap behind leaders Liverpool remains daunting.
CHERRIES STOP THE ROT
After six matches – five of which ended in defeat – without a victory, Bournemouth finally got back to winning ways against Brighton and Hove Albion on Tuesday.
Harry Wilson got the ball rolling with a driven effort from the edge of the box after Dominic Solanke teed him up in the 36th minute.
Pascal Gross then put past his own goalkeeper just before the break, diverting in after a Bournemouth corner caused havoc in the visitors' box.
Callum Wilson then wrapped up a comfortable win 16 minutes from time, rounding Mat Ryan and slotting in unchallenged, with Aaron Mooy's late effort a mere consolation in a 3-1 defeat for the Seagulls.
It was not enough to move Bournemouth out of the bottom three, though – Aston Villa's last-gasp 2-1 win over fellow strugglers Watford decisive in that sense, as Tyrone Mings got the all-important clincher.
NEWCASTLE STUN EVERTON WITH COMEBACK
Everton looked to be easing to a 2-0 win over Newcastle United – but it all went wrong in stoppage time.
Moise Kean initially put Everton in front in the 30th minute with his first Premier League goal, though he required a little luck, as he capitalised on Newcastle's inability to clear the ball and then shot under Martin Dubravka, who probably should have done better.
The in-form Dominic Calvert-Lewin got his 10th top-flight goal of the season early in the second half, but that two-goal cushion was insufficient.
Florian Lejeune was Newcastle's hero, first scoring with an acrobatic attempt after a Jordan Pickford error, then restoring parity with a volley that just about found its way over the line amid a scramble in the penalty box, both goals coming in stoppage time.
There was no such drama at Selhurst Park, however, as Southampton managed to hang on to their 2-0 lead in an ill-tempered affair, moving them into the top half of the table.
Palace's Wilfried Zaha might find himself in danger of retrospective action as well, after television cameras caught him poking James Ward-Prowse in the face during a half-time altercation.