Guus Hiddink's first Premier League match back in charge of Chelsea ended in a 2-2 draw against Watford after Oscar missed a penalty in the 80th minute at Stamford Bridge on Saturday.
With the score level, Eden Hazard was tripped by Valon Behrami. Oscar stepped up, and slipped in his run-up before blazing over.
Diego Costa gave Chelsea the lead with a volley after John Terry won a header from Willian's corner in the 33rd minute.
Troy Deeney leveled with a penalty three minutes before halftime, sending Thibaut Courtois the wrong way after Nemanja Matic's handball.
While Chelsea remains two points above the relegation zone - and 13 points from fourth place - Watford is only behind United on goal difference in seventh place.
Chelsea are heading into a clash with another team in turmoil - Manchester United - who lost 2-0 at Stoke and put manager Louis Van Gaal's job under further scrutiny.
Leicester remained on top despite Christian Benteke giving Liverpool a 1-0 victory over the surprise front-runners.
Substitute Christian Benteke struck in the 64th minute against the league leaders at Anfield, steering home a pass across goal by Roberto Firmino with a controlled finish.
Liverpool dominated the first half, with Philippe Coutinho and Divock Origi going closest for Juergen Klopp's team.
But striker Origi hobbled off injured after a promising 35 minutes, appearing to point to his hamstring. Benteke replaced him in Liverpool's attack.
N'Golo Kante almost scored for Leicester by turning a cross from Christian Fuchs toward goal, only for Simon Mignolet to make a good low save.
The defeat was Leicester's first since losing 5-2 to Arsenal on Sept. 26 - a side who can replace them atop the table if they beat Southampton later this morning.
Manchester City quickly recovered from losing at Arsenal on Monday to thump struggling Sunderland 4-1 to stay third.
City scored three goals in 11 minutes against Sunderland to decide the outcome of the Premier League match in the first half, but substitute Vincent Kompany's return from injury lasted even less time.