Tottenham powered to the top of the Premier League with an impressive 2-0 win against Manchester City, while Chelsea are up to second place after their victory at Newcastle on Saturday.
Jose Mourinho's side are two points clear of Chelsea thanks to goals from Son Heung-min and Giovani Lo Celso at the Tottenham Hotspur Stadium.
Tottenham took the lead after five minutes as South Korean forward Son ran onto Tanguy Ndombele's lofted pass, beat the City offside trap and slotted a cool finish under Ederson.
It was Son's ninth league goal this season and his 11th in all competitions.
City dominated possession after Son's goal and thought they had equalised in the 27th minute when Aymeric Laporte fired home.
But Gabriel Jesus controlled Rodri's cross with his arm before setting up Laporte and the goal was disallowed after referee Mike Dean consulted the pitchside monitor.
Lo Celso came off the bench to score with his first touch just 35 seconds after his introduction.
The Argentine midfielder netted his first Premier League goal in the 65th minute, driving his shot past Ederson after Harry Kane's sublime pass prised open the City defence.
On the one-year anniversary of Mourinho's appointment, Tottenham are unbeaten in their last eight league games since losing to Everton on the opening weekend of the season.
Mourinho's team are on a four-match winning run in the league and have been transformed into genuine title contenders just months after finishing outside the top four last term.
"The players gave everything and followed a strategy. They were amazing. Harry Kane represents the spirit of the team, and all the other guys are the same. They all want to do it," Mourinho said.
"We found a way to play and it was magnificent to see them play how they did."
Tottenham, who last won the top-flight title in 1961 and haven't lifted a major trophy since 2008, would surrender pole position if Leicester beat champions Liverpool at Anfield on Sunday.
City are languishing in 10th place, eight points behind the leaders after their first defeat in 10 games in all competitions.
Pep Guardiola's timid side look a shadow of the swaggering outfit that won successive league titles in 2018 and 2019.
Twelve points from eight games is City's lowest total at this stage of a Premier League campaign since 2008-09.
"It could be better. We played similar to how we have all season. We did not defend good for the first goal," Guardiola said.
"We had more chances than them but we lost. Mourinho's teams are like this, you make a mistake and they punish you on the counter attack."
- 'Stay humble' -
Next weekend, Tottenham face a fascinating clash with London rivals Chelsea, who maintained their fine form as Federico Fernandez's first-half own goal and Tammy Abraham's strike sealed a 2-0 win at St James' Park.
Frank Lampard's side are unbeaten in nine games in all competitions and have not lost in their last six league matches.
With five clean sheets in their last six outings in all competitions, Chelsea's third successive league victory was the perfect way to start a hectic period leading up to Christmas.
Chelsea's pressure was rewarded in the 10th minute when Mason Mount whipped in a low cross and Fernandez turned it into his own net under pressure from Ben Chilwell.
Chelsea put the result beyond doubt in the 65th minute when Timo Werner accelerated away from the Newcastle defence and slipped a pass to Abraham, who guided his shot in off the post.
"It's not an easy game. We played well in patches and the result is key in these games," Lampard said.
"I won't get excited about being top of the table for five minutes. It's important to be humble and know it's a long race."
Brighton's 2-1 success at Aston Villa ended a run of seven games without a win in all competitions.
Graham Potter's side took the lead through Danny Welbeck before Ezri Konsa's equaliser for Villa.
Solly March put Brighton back in front, but Albion defender Tariq Lamptey was sent off for a foul on Jack Grealish in stoppage-time.
Villa were controversially denied a penalty in the final seconds when Michael Oliver gave a spot-kick for March's challenge on Trezeguet, only for the referee to change his mind after consulting the pitchside monitor.