A recovering Liverpool side lost the plot Saturday after suffering a 1-0 defeat at minnow Nottingham Forest while Manchester City returned to winning ways courtesy of an Erling Haaland brace against Brighton.
Chelsea and Manchester United both missed the chance to close on the leaders as Casemiro's stoppage-time header canceled out Jorginho's 87th-minute penalty in a 1-1 draw.
City's first defeat of the season to Liverpool last weekend looked to have kick-started the Reds' season, but Jurgen Klopp's depleted side slumped to a shock defeat at the City Ground.
Forest began the day bottom of the table, but its first win since August lifted Steve Cooper's men to within one point of safety.
Taiwo Awoniyi, who spent six years at Anfield without making an appearance, scored the only goal 10 minutes into the second half.
"To score against Liverpool is a day I will never forget," said Awoniyi.
Without the injured Darwin Nunez, Diogo Jota and Luis Diaz and with Thiago Alcantara missing due to illness, Liverpool lacked the guile to break Forest down from open play.
But it did have plenty of opportunities from set-pieces as Virgil van Dijk missed three big chances.
"How we cannot score from the set pieces, I have no idea," said Klopp. "That's it pretty much. So the performance I can explain, the result not really."
The defeat leaves Liverpool still down in seventh, 11 points adrift of leaders Arsenal having played a game more.
United missed the chance to leapfrog Chelsea into fourth but was happy to salvage a point thanks to Casemiro's first goal for the club.
Scott McTominay looked to have cost the Red Devils the game when he stupidly hauled down Armando Broja from a corner late on and Jorginho coolly converted the resulting spot-kick.
Chelsea remains unbeaten under Graham Potter, but back-to-back draws leave the Blues six points behind Arsenal after they failed to hold out.
Casemiro rose highest to power in Luke Shaw's cross despite Kepa Arrizabalaga's best attempts to keep it out in the 94th minute.
"I have to make a big compliment to my team," said United boss Erik ten Hag, who had left Cristiano Ronaldo out of his squad as punishment for refusing to come on as a substitute against Tottenham in midweek.
"To fight back with a fourth game in 10 days, you see the spirit and how they deal with setbacks."
Normal service resumed at the Etihad as City moved to within a point of the top with Haaland taking his tally for the season to 22.
The Norwegian failed to score for the first time in 10 games at club level at Anfield last weekend but quickly made amends by showing his immense pace and power to latch onto Ederson's long ball, round Robert Sanchez and barrel Adam Webster off the ball to tap into an empty net.
Haaland then smashed home his 17th Premier League goal of the campaign from the penalty spot.
"He is there to score the goals," said Kevin De Bruyne of his prolific teammate. "It's just the start, he is doing what he needs to do."
Brighton is still to win under new boss Roberto De Zerbi but did push the champions back after the break when Leandro Trossard fired in at the near post.
But another piece of City brilliance, this time from De Bruyne, killed the game off as the Belgian curled in from outside the box.
Everton ended a run of three straight defeats by beating Crystal Palace 3-0 at Goodison Park.
Dominic Calvert-Lewin's return from injury is a huge boost for Frank Lampard's men and the England international showed quick feet to fire home his first goal of the season early on.
Anthony Gordon then tapped in the second just after the hour mark before Dwight McNeil rounded off the scoring six minutes from time.
The victory lifts the Toffees above Palace on goal difference into 11th.
