How far from potential Champions League winners Arsenal will feel this morning. Undermined by unusually poor defending, they collapsed to their heaviest away defeat in Europe last night. On a freezing, humiliating evening there was nothing to warm the few hundred visiting fans.

They will wonder, though, what might have been. Ahead through Silvinho after 118 seconds, Arsenal will look back with regret at a dreadful miss by Nwankwo Kanu minutes later. At 2-0 it could have been game over. Instead they were outclassed by a wonderfully lively, inventive Spartak side.

This was a fantastic game which belied the poor pitch conditions but Arsenal will care little for that. Their match at home to Bayern Munich in a fortnight must surely be won if they are to progress to the quarterfinals and there is little margin for error any more. Individual mistakes at the back and the ease with which they were torn apart in the second half do not bode well.

The absence of Patrick Vieira and Gilles Grimandi from central midfield hardly helped. But Tony Adams was out of sorts on his return and Martin Keown also failed to handle the outstanding Brazilian forwards Marcao and Robson. On the coldest night of Moscow's winter, when the temperature was 10C at kick-off and falling, it was ironic that boys from Brazil scored four times.

"We conceded stupid goals we are not used to conceding," said Arsenal's manager Arsene Wenger. "My team gave everything to play well but defensively as a team we didn't look as solid as we are used to.

"We should have scored a second goal when we were 1-0 up. Unfortunately we couldn't do it and then we had problems in the second half with the quick collective pace of Spartak's passing and we dropped physically."

Disciplined, tough and skilful, Spartak were fantastic to watch at times. Their passing, pace and movement was excellent, with Vasily Baranov a constant menace down the right side. They have now won all four of their Champions League matches at this impressive stadium. Long before the end Arsenal must have wished this had never started.

The impressive Thierry Henry had already gone clear once before he set up Silvinho to carry the ball wide of the goalkeeper Alexander Filimanov and score comfortably. When Henry finished a fine run from the halfway line by setting up Kanu it seemed game over. The Nigerian, though, is out of form and lacking confidence and from a few yards he allowed the goalkeeper to save.

Spartak had already gone close twice when Silvinho failed to clear and Marcao fired a first-time shot beyond Manninger's reach. The noisy, excitable 75,000 crowd went wild and there was better to come.

Poor marking proved costly as JerryChristian Tchuisse crossed from the right and Robson headed across for Marcao to slot in from around two yards. Shortly after the Brazilian set up Egor Titov and, when Adams stumbled, Titov finished unerringly.

There was still time for Robson to round Manninger nine minutes from the end to complete a miserable, humbling night on which Ray Parlour picked up a booking which means he misses the next match. Arsenal's supporters deserved better than to be ignored by so many of their players.

Spartak Moscow: Filimonov; Kovtun, Christian Tchuisse, Ananko (Bushmanov 88), Baranov, Bulatov, Titov, Parfyonov, Bezrodny; Marcao, Robson.

Arsenal: Manninger; Luzhny, Adams, Keown, Silvinho; Parlour, Ljungberg, Pires (Lauren 70), Vivas, Kanu (Wiltord 66), Henry. Attendance: 70,000.

Referee: P Collina (Italy).