Manchester City fought back from 3-1 down to rescue a thrilling 3-3 draw against Newcastle, while Edouard Mendy's embarrassing blunder condemned Chelsea to a 3-0 defeat at Leeds on Sunday.
Pep Guardiola's side was in danger of a first league defeat since February after falling 3-1 behind in the second half at St. James' Park.
But Erling Haaland sparked defending champion City's revival with his third goal for the club before Bernardo Silva's equalizer completed the escape act.
Second-placed City remains unbeaten with seven points from its first three games, leaving it two points behind leader Arsenal.
While Guardiola will be concerned with the way City was carved open by Newcastle, the spirited comeback underlined why it has won the title four times in the last five seasons.
"That was a proper game. Newcastle are becoming one of the toughest opponents for sure," Guardiola said.
"To see the team fight to the end is enough. The Premier League is so difficult for everyone.
"It shows how amazing we've done for five years and how difficult it will be."
City needed just five minutes to take the lead as Silva cleverly worked space to cross towards the unmarked İlkay Gündoğan, who fired home from eight yards.
Newcastle equalized in the 28th minute when Allan Saint-Maximin's pin-point cross was bundled in by Miguel Almiron, with the goal awarded by video assistant referee (VAR) after an initial offside flag.
Having conceded for the first time in the league this season, City's defense was breached again in the 39th minute.
Saint-Maximin was City's tormentor again with a brilliant run and pass to Callum Wilson, who timed his run perfectly to slot past Ederson.
Kieran Trippier grabbed Newcastle's third goal with a stunning free kick that whistled into the top corner after 54 minutes.
But Haaland reduced the deficit with a close-range strike from Rodri's flick on the hour.
City had a lifeline and Silva seized it four minutes later with a deft finish from Kevin De Bruyne's pass.
Mendy misery
At Elland Road, Mendy's costly 33rd-minute mistake was the catalyst for Chelsea's shocking implosion as Brenden Aaronson netted after catching the goalkeeper taking too long in possession.
Rodrigo's fourth goal in three games this season doubled Leeds' advantage in the 37th minute.
Jack Harrison's 69th-minute goal completed Leeds' first win over Chelsea since 2002 and the biggest against its old rivals since 1995.
Adding to Chelsea's misery, its Senegal defender Kalidou Koulibaly was sent off for a second booking after tripping Joe Gelhardt in the 84th minute.
Chelsea finds itself in the unusual position of sitting below its less glamorous west London neighbors Fulham and Brentford in the table.
Thomas Tuchel's side has taken four points from its first three games and the German was alarmed at the way his expensively rebuilt team faded after Mendy's howler.
"Everything that can go wrong, did go wrong. We lost the game in the first 20 minutes, where we were clearly better and had huge chances," Tuchel said.
"What do you expect if you present two goals to an opponent in the Premier League? We give goals away from huge individual errors too often."
At the London Stadium, Brighton added to West Ham's woes with an impressive 2-0 victory.
Alexis Mac Allister put Brighton ahead in the 22nd minute after Danny Welbeck was fouled by West Ham's debutant defender Thilo Kehrer.
Kehrer claimed the foul had taken place outside the penalty area, but a VAR check decided it was just inside and Mac Allister calmly converted the spot kick.
Leandro Trossard raced through to bag Brighton's second goal with a composed finish past Lukasz Fabianski in the 66th minute.
Brighton is in fourth place with seven points from their first three games, while West Ham slumped below Manchester United to the bottom of the table.