AS Monaco 3 Chelsea 1Chelsea were so stunned by this defeat that it will be hard for them to clear their thoughts and recover at Stamford Bridge in the second leg of this semi-final. They seemed to hold all the advantages, including the dubious one of an extra man when apparent play-acting by Claude Makelele led to the dismissal of Monaco's Andreas Zikos in the 52nd minute.
The score was then 1-1, with Chelsea looking by far the more substantial team. It took remarkable lapses of concentration for them to let the indefatigable Monaco come back with goals from Fernando Morientes and, with his very first touch, the substitute Shabani Nonda.
Chelsea had laid sensible plans but could not have anticipated this.
Despite the resources of an extensive squad, this was one of the easier team selections for Claudio Ranieri to make. There was little risk that the manager would antagonise employers who are already sceptical about him by a new excursion into eccentricity.
In view of Monaco's average scoring rate of over three goals a home match in the Champions League this season, Ranieri was prepared to count on the resilience that is Chelsea's strongest suit. The one obvious concession to adventure saw the selection of Jesper Gronkjaer on the left, where Damien Duff was ruled out by ill health.
The sight of Monaco taking the lead as early as the 16th minute could have been taken as ridicule of the manager's planning, but the emphasis on solidity gave Chelsea a solid platform. Before and after their swift equaliser, Chelsea looked as if they were well equipped to pin Monaco back.
In the early, nervous exchanges, Ranieri's men were working smoothly, with John Terry getting across smartly to cover just when Dado Prso was on the verge of bursting away from the other centre-back, Marcel Desailly.
Although there was greater alarm when Ludovic Giuly got behind Wayne Bridge, sufficient resources were mustered to ensure that Lucas Bernardi's effort from the cut-back was blocked.
An individual misjudgment, all the same, can lead a team into trouble.
Mario Melchiot's habitual impulsiveness had him lunging once Patrice Evra had fed the nimble Jerome Rothen on the left. The winger had lost control of the ball, but Melchiot brought him down to earn a booking that was just the initial punishment.
Rothen flighted the free-kick, with a deflection and a bounce adding to the confusion, before Prso put a strong header high into the corner of the net.
It was only the second goal Chelsea had conceded in Champions League away matches this season and it would have been excusable if they had been nonplussed for a while.
The side that fought back to beat Arsenal in the quarter-finals has a stronger spirit in this competition. To the surprise of the home crowd, Didier Deschamps' side were forced to adopt a counter-attacking style for the remainder of the first half. With their defence struggling, this was no cunning plan by Didier Deschamps' men, just a desperate necessity.
Chelsea's midfield was especially remorseless, while Eidur Gudjohnsen was a lively target for their services. The Icelander could not make a clean connection when Scott Parker forced in a cross, but the ball ran for Hernan Crespo to finish confidently.
The Argentinian, with his marksmanship hidden by a multitude of injuries, has tried his own patience and that of the club, but here he had an invitation to reclaim his prior fame as one of the Champions League's deadliest forwards.
Further harm was to come to Monaco with the highly dubious red card for Zikos. They had just begun to rediscover sharpness, with Marco Ambrosio parrying one header by Prso and Desailly putting a foot in the way of the other, when the incident between Makelele and the Greek midfielder took place.
They had slid into one another just before Ambrosio cleared. As the pair got up, Makelele clipped Zikos on the head. The Monaco player then responded in kind and the Chelsea midfielder took a pace before falling to the ground as if he had taken a serious blow.
The referee, Urs Meier, cannot have seen the incident in its entirety and showed the red card to Zikos. By draconian interpretation, both men could have been dismissed for raising their hands, but it is debatable if the conduct involved could be termed violent at all.
There was to be an astonishing healing for Monaco with the equaliser. After the Chelsea substitute Jimmy Floyd Hasselbaink headed lamentably wide after a dynamic break by Bridge in the 78th minute, Monaco poured men into the area that the Chelsea left-back had vacated.
Play was switched to that flank and Morientes advanced to drill a bouncing ball past Ambrosio at the near post.
If Chelsea were still telling themselves that a 2-1 defeat was tolerable, Monaco had a higher target in mind. Nonda trotted on to the pitch as a substitute and with his first touch converted Rothen's cross.
This tie had become a baffling menace to Chelsea.
MONACO: Roma, Evra, Ibarra, Bernardi, Giuly (Nonda 83), Prso (Cisse 57), Morientes, Zikos, Rothen (Plasil 89), Rodriguez, Givet. Subs Not Used: Sylva, Oshadogan, Adebayor, El Fakiri. Sent Off: Zikos (53). Booked: Ibarra. Goals: Prso 17, Morientes 78, Nonda 83.
CHELSEA: Ambrosio, Makelele, Desailly, Lampard, Melchiot (Hasselbaink 62), Bridge, Parker (Huth 69), Crespo, Gudjohnsen, Terry, Gronkjaer (Veron 46). Subs Not Used: Sullivan, Mutu, Cole, Geremi. Booked: Melchiot, Makelele, Terry. Goals: Crespo 22.
Referee: Urs Meier (Switzerland).