LONDON (Reuters) - Chelsea's shock defeat at home to Premier League strugglers Crystal Palace on Saturday offered their rivals a glimmer of hope that they can yet rein in the runaway leaders who had appeared to be cruising to the title.
Chelsea face a crunch match at home to challengers Manchester City on Wednesday. Another loss for the Londoners, combined with a win for second-placed Tottenham Hotspur who visit Swansea City on the same night, would cut Chelsea's lead to just four points with eight games to play.
Of course, one poor result does not change the big picture. Chelsea remain in the driving seat to win their sixth league title in coach Antonio Conte's first season in charge.
Their current lead of seven points over Spurs is an enviable position from which to contemplate the tail-end of the campaign which ends in May.
But there are some worrying signs for Chelsea fans that the next few weeks could be more nerve-wracking than had seemed likely to be the case.
Before the defeat to Palace, Chelsea's previous league match was a hard-fought 2-1 win away to Stoke City which was settled only by a last-gasp winner by defender Gary Cahill.
Star striker Diego Costa racked up 13 Premier League goals before Christmas but has struggled to keep up that form, scoring only four times since then.
And Chelsea's defence, which went six consecutive league games without conceding a single goal between October and November, has now failed to keep a clean sheet in seven.
All of this may prove to be a mere blemish in a season which, so far, has seen Chelsea dominate the push for the title.
Even on Saturday, Chelsea had nearly 75 percent of the possession of the ball and wingers Pedro and Eden Hazard looked dangerous just as they have throughout the season. Chelsea were thwarted by a remarkably resolute display by Palace's defence, marshalled by the impressive Mamadou Sakho.
Chelsea fans showed little sign of nervousness, although there was no rendition of the chant "We're going to win the league" which had begun to be sung in recent weeks.
Coach Antonio Conte said the defeat only backed up his caution when asked in recent weeks by reporters about Chelsea's apparently unstoppable bid for the title.
"I always said the league only finishes when you have the mathematics you want. Otherwise, you must fight and play every game to win because in England an easy game does not exist," he told reporters. "Today we deserved at least to draw because we had many chances to score and we dominated the game."
Reporting by William Schomberg; Editing by Toby Davis