WHEN does a procession turn into a panic? Surely next weekend, if Chelsea fail to beat West Ham.

At the start of March, the race for the Premiership title was over. Chelsea's champions elect enjoyed an 18-point lead over a faltering Manchester United and Sir Alex Ferguson's men had recently shipped four goals at Blackburn. The destination of the Premiership trophy was a fait accompli.

Now though, at the start of April, things are starting to look different. Chelsea's lead is down to seven points following Saturday's inability to score against a Birmingham side who had conceded ten in last month's games against Liverpool and Manchester United.

United, for their part, are on an eight-game Premiership winning streak and have rediscovered the attacking verve that once entitled them to Chelsea's crown. With six games of the season to go, people are starting to think the unthinkable.

Yet can Chelsea really complete one of the greatest capitulations of all time? The Londoners need only win their three remaining home games to secure their second successive title. Given that one of those is against United, though, the task is not as simple as it may seem.

Whereas once the Chelsea juggernaut was steamrollering everything in its path, now its constituent parts are slightly out of synch.

Neither Didier Drogba nor Hernan Crespo are enjoying any sustained success in front of goal, both Damien Duff and Arjen Robben are offering little more than a peripheral presence on the flanks, and even Frank Lampard appears drained at the end of a season that has rarely been free of controversy.

The spark is missing from much of Chelsea's play - especially away from home - and opponents seem to have discovered that a smothering man-for-man system in midfield is the best way to negate their undoubted attacking strengths.

If the leaders are unable to break down Birmingham, it is unrealistic to assume that they will automatically brush aside far more resilient opponents when they travel to Bolton and Blackburn before the season's end.

Manchester United, on the other hand, are flying. When a side are able to leave out a player like Ruud van Nistelrooy, it is a sure sign that goalscoring is anything but a problem.

With Louis Saha and Wayne Rooney playing to the peak of their form, and a resurgent Ryan Giggs bolstering an attacking unit that already boasts the mercurial Cristiano Ronaldo, United are rediscovering the flamboyancy of old. At the other end, even Rio Ferdinand has a spring in his step.

Yet the feeling still persists that they have left it too late. To snatch the title, United are almost certainly going to have to win all six of their remaining games, and that includes the April 29 showdown at Chelsea.

It is not out of the question, but it is a monumental ask and even that would not guarantee the title. For all of Chelsea's recent faltering, it is surely too much to expect them to slip up in relatively simple home games against Everton and West Ham.

This month's meeting of the top two could yet be academic of course, if United slip up in their own tricky fixtures between now and then. Next weekend's home game with Arsenal will be a fevered affair, even if the Gunners are looking ahead to a Champions League semi-final, and Easter Monday's trip to Tottenham is hardly without risk, despite Spurs' error-strewn display at Newcastle last weekend.

Assuming they stay unbeaten, though, it will be interesting to see how Chelsea react to being placed under intense pressure on their own soil.

They lost both their shape and composure when Barcelona visited Stamford Bridge and a repeat of that slipshod display would seriously undermine their claims to English supremacy.

Its still looks like that supremacy will be confirmed. But at least we have the semblance of a battle and, for much of the season, that looked unlikely in the extreme.

Responding to adversity is the test of true champions. It is good for everyone that Chelsea are being asked to do just that.