Table-topping Chelsea travel to play West Bromwich Albion on Tuesday with manager Jose Mourinho continuing to play down his side's chances of winning the Premier League title.
Chelsea (17-5-3) went top of the league after beating Newcastle 3-0 at home Saturday with in-form Edin Hazard scoring his first hat trick for the Blues.
"We are playing well," Mourinho said after the Newcastle match. "The first half was not the best, but we have been playing well for a long time.
"Individually, we are in a good moment and the team is getting results and we are top of the league. It's something we can't hide from, but I still say the same, I don't change. We won't win the league."
Arsenal started the weekend as leaders but slumped to a heavy 5-1 defeat at Liverpool, while second-place Manchester City, whom Chelsea beat 1-0 at the Etihad last Monday, were held to a frustrating goalless draw at Norwich City.
Chelsea, who are now one point ahead of Arsenal and two ahead of City, have the chance to extend their lead at The Hawthorns against a West Brom side battling against relegation.
A cautious Mourinho is not underestimating the task facing the Blues against Albion.
"It's a difficult stadium and they have a fantastic crowd," the Chelsea boss said. "They defend well and have physical players for attacking and defensive set-pieces. Their midfield is well organised and they have talent in attack.
"(Zoltan) Gera is back, he wasn't in the team for a long time. We only have two days to rest but it's the same for both, only Arsenal have one day more. Arsenal played today and Manchester United play tomorrow, so they have 24 hours more but it happens."
The Baggies (4-11-10) dropped into the bottom three after losing 3-1 at Crystal Palace on Saturday and have taken only two of a possible 15 points since their last league victory - a 1-0 home win against Newcastle on New Year's Day.
West Brom were well beaten at Selhurst Park, but would have been cheered by the immediate impact of on-loan striker Thievy Bifouma, who came on for his Premier League debut at halftime and scored after just 36 seconds when he finished off a neat one-two with Victor Anichebe.
Pepe Mel, who was appointed West Brom head coach last month as replacement for the sacked Steve Clarke, is still looking for his first win with the Baggies after two draws and two defeats.
Mel's side played well in their last home match against high-flying Liverpool and earned a 1-1 draw against the Merseysiders.
The Baggies are 18th in the table on 23 points from 25 games, with only 13 league matches remaining to play.
"Now we have 13 very important games to ensure West Brom are in the Premier League," said Mel. "The first thing is to try and win the game on Tuesday, and if we want to stay in this league we must play like we did in the second half against Liverpool last weekend and the second half today.
"We have 13 cup finals and 13 battles and we must win as many as we can - and the players must come with me in this battle."
A controversial stoppage-time penalty converted by Hazard salvaged Chelsea a 2-2 draw against West Brom at Stamford Bridge on Nov. 9. Samuel Eto'o opened the scoring for the Blues before Shane Long and Stephane Sessegnon struck twice to give Albion the lead until Hazard's last-gasp equaliser.