WHO are these guys? Liverpool have made themselves one of the great soft touches of the Barclays Premiership, but when it comes to the European Cup they suddenly turn into men of hard minds, stern resolve and nerveless control. Last night they drew the teeth from a Chelsea side that had been the terror of all teams in the league — including Liverpool themselves.

A goalless draw is far more to Liverpool’s taste than Chelsea’s. The tie is still nicely balanced, but after last night’s stirring effort, Liverpool might just feel that the force will be with them in the second leg at Anfield on Tuesday.

All semi-finals look for an individual to find a great performance. But when that doesn’t come — and it generally doesn’t in these tense circumstances — you start to look for a moment. Nothing more, but a moment when someone steps up. Sometimes it is the man you expect, more often the man you have forgotten, a player who for some unknowable reason does something far beyond his usual capacity. Last night, Chelsea looked hard for that moment and that man, and looked in vain.

Liverpool arrived determined not to lose, an understandable and, after their goalless draw against Juventus in the quarter-final second leg, clearly attainable ambition. When that sort of game plan works well, you can make the best players in the world look silly. And once you have begun to do that you are three-quarters of the way there. Liverpool came to Stamford Bridge with the lofty ambition of making some of the best players in the world feel silly and they made a pretty decent job of it.

Chelsea spent much of the match looking baffled as much as anything, like men confronting a new and altogether unacceptable reality. This Liverpool team were nothing like the side they had beaten three times this season. That is one of the strange illusions that football can produce in high-stakes matches, matches that matter rather more than is really comfortable for anyone on the pitch.

Semi-finals in any competition are traditionally like Doctor Who — more celebrated for their suspense and the fraught nerves of the audience than for any great coherence of plot. That rule holds good for a semi-final in the League Cup, but it is doubled and redoubled for the semi-finals in the European Cup. The problem is that the qualities that got you there are not necessarily those that will take you to the level beyond. Last night, Liverpool found additional qualities while Chelsea did not. That was the story of the night.

In any semi-final, it is not so much the prize that dominates the hearts and minds of the players as the horrors of missing out. Both sides played in dread of the thought that all that work, all that skill and all that luck might all be in vain. Both sides played as if they knew that the Daleks were coming.

Of course, it all meant “so much” to both clubs. It always does. But at least in this evening of ritual nerve-shredding, it meant different things to each club. Liverpool were trying to live up to a history of success, albeit an increasingly ancient one. Chelsea were trying to escape from a history of what is these days always referred to as “underachievement”. It is a football word that means failure.

It is presumably a banned word in the newly bellicose and newly plutocratic Chelsea. Increasingly this season, Chelsea’s play has been marked by a growing self-belief. Instant aristocrats, you would have thought — from trade to a dukedom in a generation and carrying it all as if born to it. They have cut through the league as it were a personal fiefdom.

But it is an occasion such as this that finds you out. There is not much bottom to a tradition, a history, a generation, a culture that is less than two years old. Chelsea have this season created a swaggering self-confidence, yes. But they don’t have the very particular kind of self-confidence that you need at this higher level of competition.

Chelsea found themselves trying to build a tradition rather than build on one. And that’s not the same thing at all. Last night, Chelsea were making it up as they went along. It was Liverpool who knew their lines.

So much so that the one Chelsea player who caught the eye was Petr Cech, the goalkeeper. All this stuff about making some Chelsea outfield player the player of the season is arrant nonsense. Cech saved well from John Arne Riise and then outstandingly from Milan Baros.

Goalkeepers of that quality are like femmes fatales: deliberate, calculating breakers of hearts. No one’s heart was quite broken last night, but Chelsea’s may just have suffered a hairline crack.