Chelsea may have restored some breathing space over Manchester City with a 2-0 win over Newcastle United on Saturday but they have not regained the form that made them runaway title favourites earlier in the season.
Chelsea pull clear as Man City held by Everton
Goals in each half from Oscar and Premier League top scorer Diego Costa (15) kept up the London club's record of winning every home league game this term.
Victory was a relief for the leaders after their title campaign suffered a serious blow with a shock 5-3 defeat to Tottenham Hotspur on January 1.
Chelsea lacked the quick one-touch passing
While Chelsea were winning on Saturday, City could only draw 1-1 at Everton, allowing Jose Mourinho's men to open a two-point lead over their nearest rivals.
But the scoreline at Stamford Bridge belied an often nervous performance by Chelsea who were outplayed in the first half by an under-strength Newcastle who have yet to appoint a manager to replace new Crystal Palace boss Alan Pardew.
Moussa Sissoko hit the angle of post and bar after 37 minutes. Earlier, Remy Cabella forced a good one-handed save from goalkeeper Petr Cech, replacing Thibaut Courtois (broken finger).
For much of the game Chelsea lacked the quick one-touch passing and movement that helped put them eight points clear of City a little more than a month ago.
Playmaker Eden Hazard was outmuscled, Cesc Fabregas was low-key in midfield and Costa seemed off the pace.
‘We didn't have enough players playing quite at the level we are used to seeing in the first half’
But it was Chelsea who took the lead against the run of play two minutes before halftime when Brazilian Willian caught Newcastle off guard with a quick corner.
Branislav Ivanovic fired the ball across goal and Oscar scored from close range at the far post.
Oscar played a role in Chelsea's second too, back-heeling the ball into the path of Costa who rounded off a flowing move with a crisp shot.
Assistant coach Steve Holland conceded Chelsea were off form in the opening period.
"We didn't have enough players playing quite at the level we are used to seeing in the first half," he said.
"The manager reminded one or two of them at halftime what was required. There was a very good response from the players and it was much more like it in the second half."
Mourinho did not talk to the media after being charged with misconduct by the FA on Thursday over recent comments.