Chelsea's worst winless Premier League run under Thomas Tuchel was extended to four games as they were held to a 1-1 draw at Brighton and Hove Albion on Tuesday.
Tuchel's side missed a chance to quickly close the gap to leaders Manchester City, who beat the European champions 1-0 at the Etihad Stadium on Saturday to go 13 points clear.
Hakim Ziyech put the Blues ahead in the first half at the Amex Stadium, but Brighton restored parity through an unmarked Adam Webster in the 60th minute.
Chelsea were unable to bring an end to their worst top-flight run under Tuchel by finding a winner, with Brighton earning an impressive point.
Brighton started positively and pressed Chelsea well, but Danny Welbeck spurned their best opportunity when he failed to connect with the ball in the six-yard box.
However, Chelsea took the lead in the 28th minute when a speculative Ziyech effort got the better of Robert Sanchez and found the bottom-right corner.
The Seagulls made a strong start to the second period and drew level on the hour mark when Webster powered a header home from Alexis Mac Allister's corner.
Romelu Lukaku made a brilliant dart in behind to latch onto Antonio Rudiger's lofted throughball but was thwarted by the onrushing Sanchez, with the Blues having to settle for a draw.
What does it mean? Still concern for Tuchel
After a run of three wins in nine games in all competitions across December and January, Chelsea looked to have got back on track by beating Tottenham in the EFL Cup semi-finals and thrashing Chesterfield in the FA Cup.
However, on the south coast they were unable to bounce back from the disappointment of defeat at City, which effectively brought an end to any faint title hopes they may have had.
Lacklustre Lukaku
Tuchel has been frustrated by the performances of Chelsea's attackers this season and Lukaku did little to appease him here. Although he supplied two key passes, he had just eight touches in the first half and only managed one shot on target in the whole game.
Webster unwatched
Webster was allowed to steam in completely unmarked from the back post and send a bullet header past Kepa Arrizabalaga for the equaliser. Tuchel's men showed a lack of awareness when defending the set-piece.
What's next?
Chelsea will welcome their former coach Antonio Conte back to Stamford Bridge when they face Tottenham on Sunday, when Brighton travel to Leicester City.