Manchester City opened up a 13-point lead at the top of the Premier League as Kevin De Bruyne's sublime strike beat Chelsea 1-0, while Philippe Coutinho enjoyed a dream Aston Villa debut to rescue a 2-2 draw against Manchester United on Saturday.
Everton boss Rafael Benitez is reportedly on the verge of being sacked after a 2-1 defeat at Norwich that lifted the Canaries to within a point of safety as Newcastle and Watford played out a 1-1 draw.
De Bruyne broke Chelsea's resistence 20 minutes from time at the Etihad Stadium when the Belgium midfielder escaped N'Golo Kante and bent a perfectly-placed shot into the far corner of Kepa Arrizabalaga's goal from 20 yards.
City's 12th successive league win effectively ended the Blues' title aspirations.
Third-placed Liverpool can close the gap at the top to eight points with their two games in hand, but it would a collapse by the champions to deny them a fourth title in five seasons.
"In January no-one is champion," said City boss Guardiola.
"All the players gave everything and it was an important victory because they are a big contender."
But after the game, the German was critical of Romelu Lukaku, who gave the latest in a long list of subdued displays since his club record transfer from Inter Milan last year.
"Sometimes he has to do the service. He had many ball losses and a huge chance. Of course we want to serve him but he's part of the team." Tuchel said.
"The performance up front in the first half, we can do much, much better."
At Villa Park, the absence of Cristiano Ronaldo due to injury brought the best out of Bruno Fernandes.
The Portuguese had been United's talisman in the 18 months prior to Ronaldo's return to Old Trafford, but had scored just once since September.
Fernandes had a helping hand from Villa 'keeper Emilano Martinez, who let his long range strike slip through his legs to open the scoring on six minutes.
A thumping finish from the midfielder midway through the second half looked to have got United back to winning ways in the league.
But Jacob Ramsey pulled a goal back before Coutinho marked his return to the Premier League in style by firing home Ramsey's cross.
United remain seventh, still five points adrift of the top four.
- Benitez on the brink -
Benitez's unhappy spell at Everton looks like coming to an end before the face Villa next weekend after Norwich snapped an eight-game winless streak thanks to two goals in two minutes at Carrow Road.
Everton defender Michael Keane turned into his own net to open the scoring before Adam Idah poked past Jordan Pickford.
Richarlison reduced the deficit with an audacious overhead kick on the hour mark.
But it wasn't enough for the Toffees and Benitez, already disliked after his spell with Everton's Merseyside rivals Liverpool, was met with a banner saying "get out of our club' banner" at full-time.
Joao Pedro's late leveller for Watford at St. James' Park means Newcastle remain in the bottom three.
Allan Saint-Maximin gave the Magpies the lead early in the second half, jinking past two defenders before drilling a superb low strike beyond Ben Foster.
But Newcastle failed to add a killer second goal and Pedro made them pay with an 88th minute equaliser, the Brazilian thumping a header past Martin Dubravka from Kiko Femenia's cross.
Newcastle, who gave a debut to New Zealand striker Chris Wood after his move from Burnley, slipped to second last and remain two points behind fourth-bottom Watford.
Wolves beat Southampton 3-1 at Molineux to extend their unbeaten league run to four games.
Raul Jimenez, Conor Coady and Adama Traore were on target for Bruno Lage's men, who are now just six points off the top four.