Chelsea were frustrated by West Ham in a goalless draw which saw Jose Mourinho's men fall three points behind Barclays Premier League leaders Manchester City.
Mourinho on Tuesday played down his side's title chances this term and the Blues saw a seven-game winning run ended by a West Ham side battling relegation and, after leaking goals in recent weeks, defensively resolute.
City, Chelsea's opponents next Monday, scored nine in the two-legged Capital One Cup semi-final with the Hammers, but the Blues faced a defensive wall they could not breach.
Chelsea had won five successive league games and were anticipated to have a comfortable evening against a West Ham side with five points from the previous nine games and deep in the relegation mire.
Yet it was anything but easy as the Blues, who won 3-0 at Upton Park in November, found West Ham to be defensively resilient and organised, while also posing an early threat.
Andy Carroll slipped at the far post with Cesar Azpilicueta in close attendance after seven minutes and referee Neil Swarbrick was unmoved at the Hammers' penalty appeals, much to Sam Allardyce's frustration.
Oscar's curled effort was helped on to the bar by Adrian and Petr Cech scrambled clear a James Tomkins header before the West Ham goalkeeper saved from John Terry and Samuel Eto'o late in the first half.
Mourinho was incensed by a Joey O'Brien tackle from behind on Willian which saw the left-back booked and fortunate not to make more contact and earn a red card. West Ham did finish the game with 10 men when O'Brien departed with a damaged shoulder after an off-the-ball Gary Cahill push before a corner.
As Chelsea's inability to cut open the Hammers grew in the second half, they longed for a player with the guile of Juan Mata, now at Manchester United, but West Ham held on to move on to Saturday's home encounter with Newcastle with renewed optimism.
West Ham started well and Azpilicueta - restored in place of Ashley Cole as one of six changes from Sunday's defeat of Stoke - survived a scare when Carroll chested down a cross to the far post and slipped with the Spain full-back in close attendance.
Allardyce was swiftly off his bench in protest, knowing how important an early goal would be for the Hammers to win at Stamford Bridge for the first time since September 2002.
After Oscar's curling effort was tipped on to the bar by Adrian, the visitors had another opportunity.
Stewart Downing's cross found Tomkins on the penalty spot and the defender headed firmly downwards, leaving Cech to awkwardly claw the ball just out of the reach of Kevin Nolan.
Willian, Eto'o and Ramires blazed over as Chelsea were limited to shots from range.
Mohamed Diame's fall over the advertising hoardings resulted in a change, with Matt Jarvis replacing the Senegal midfielder, who limped off pointing at his right knee.
Adrian twice had to be alert, saving a Terry header with his feet before turning an Eto'o shot around the post.
West Ham's threat was limited to long balls directed to Carroll, which Cahill and Terry, who caught the Hammers striker with an accidental flailing arm on one occasion, dealt with.
Chelsea showed more urgency after the break.
Oscar shot straight at Adrian, there was no-one in the six-yard box to meet a Willian cross and Ramires fired wide from an Azpilicueta cross.
O'Brien's challenge on Willian was an outlet for Mourinho's frustrations before Chelsea earned a reprieve when Carroll swung at thin air when Downing crossed towards him.
Mourinho brought off Azpilicueta and Mikel for Frank Lampard and Nemanja Matic, switching Ivanovic to the left of a three-man defence and pushing the substitutes into midfield.
Lampard had scored three times in his previous two contests with his former club and had half-chances to add to the tally.
Little was coming off for Chelsea and, in another attacking substitution, Mourinho threw on another ex-Hammer in Demba Ba for Oscar, while Antonio Nocerino came on for his West Ham debut.
O'Brien went off as the Hammers faced four minutes of stoppage time a man short and Adrian saved from Ba before Eden Hazard shot wide and had an effort saved.
Adrian placed the ball on his six-yard box after being awarded a free-kick in the follow up to Hazard's shot, but Eto'o put the ball in having not heard the whistle.
Lampard was denied in the 97th minute by a fine Adrian save as the Hammers earned a valuable point and denied Chelsea an eighth successive win in all competitions.