Manchester City took a giant step towards the title as they beat Manchester United 2-1 at Old Trafford to clinch a record-equalling 14th successive Premier League victory.
In the second derby in Anfield on Sunday, Wayne Rooney’s late leveller gave Everton a 1-1 draw with Liverpool.
City drew level with Arsenal’s previous record winning streak, set between February and August 2002, thanks to Nicolas Otamendi’s second-half winner.
Pep Guardiola’s side are now 11 points clear of second-placed United, who were beaten at Old Trafford for the first time in 41 games in all competitions.
Guardiola’s latest success at the expense of old rival Jose Mourinho could drain much of the drama from the title race as it would take an epic meltdown for City to surrender their substantial lead.
Mourinho conceded the title is City’s, saying: “Probably, yes. The advantage is a very good one.”
United felt they should have had a late penalty for Otamendi’s challenge on Ander Herrera, but the midfielder was booked for diving.
“Manchester City are a very good team and they are protected by the luck, and the gods of football are behind them,” Mourinho said of the decision.
Guardiola dismissed Mourinho’s complaints and told the United chief to stop making excuses.
“Last season it was the same –- we won here and it was the referee. Today as well. Yesterday he spoke about the referee. We are an honest team,” he said.
“We had 75 percent ball possession, which means we wanted to play. We came here and did that.”
Having bossed the first half, City’s pressure was rewarded in the 43rd minute.
Kevin De Bruyne’s corner was flicked on and, with Ashley Young playing David Silva onside, the Spaniard hooked home from close range.
Mourinho’s team were gifted an equaliser in first-half stoppage time when City defender Fabian Delph made a hash of clearing and Marcus Rashford pounced to slot past Ederson.
But United returned the favour with an even more farcical piece of defending in the 54th minute.
Silva’s free-kick should have been cleared by Romelu Lukaku, but instead the Belgian slammed a panicked clearance into the back of United team-mate Chris Smalling and the ball looped towards Argentine defender Otamendi, who stretched to fire home.
At Anfield, Liverpool had taken the lead in the 229th meeting of the old rivals when Mohamed Salah spectacularly curled home from the edge of the penalty area in the 42nd minute.
It was the Egypt winger’s 13th goal in 12 games and 19th of season, but the Reds were unable to find a killer second.
Everton kept their discipline and refused to wilt and were awarded a spot-kick when Dejan Lovren barged over Dominic Calvert-Lewin.
Rooney, who rejoined his boyhood club from Manchester United in July, claimed the first Merseyside derby goal of his career as he drilled the penalty down the middle with 13 minutes left.
Reds boss Jurgen Klopp was furious with the penalty decision.
“I don’t understand why the ref is doing that. Lovren doesn’t make a challenge,” Klopp said in a tetchy television interview.
“If you think it is a penalty say so. Does my opinion change anything?
“I only want to speak to people with a little bit of understanding about football.”
Klopp’s surprise decision to rest in-form forwards Philippe Coutinho and Roberto Firmino backfired, but the German refused to accept blame, opting to criticise Everton for a defensive display.
“Only one team is trying over 95 minutes to win it. The other team are not in our box and didn’t have a shot on target bar the penalty,” he said.