Manchester United lost to French opposition in European competition for the first time in their history last night, a defeat that may ultimately do no more than delay their progress through to the next phase of the Champions League.

However, the punishing by Marseille of what was a rather insipid display does mean that the European champions will be required to produce a somewhat more adept performance when they travel to face Croatia Zagreb next week, though the defeat would have been more costly but for Sturm Graz's surprising 1-0 win over Zagreb in Austria last night.

It was only after the French had scored midway through the second half that United saw fit to show more adventure.

Arguably the most meaningful work of the day had been undertaken some eight hours before kick-off after a local referee had inspected the pitch and declared it all but unplayable. Panic duly set in.

More than 12 hours of incessant and, it must be said, unexpected rainfall had reduced the playing surface to a sodden mass and despite the best efforts of a small army of diligent volunteers with pitchforks and mops standing water was clearly visible down both touch-lines. Indeed, the game was given the all-clear only after a second inspection late in the afternoon.

The United squad's traditional pre-match meander across the battlefield was subsequently undertaken solemnly; there was much shaking of heads, much muttering of profanities. Conditions can influence the outcome of matches but so too can the emptying of a treatment room.

With Roy Keane and Ryan Giggs now restored to health and to his midfield, Alex Ferguson was able to send out what many would contest is his strongest team.

The only question was answered in Mark Bosnich's favour, the young Australian goalkeeper selected ahead of Raimond van der Gouw for his first appearance on the European stage this season.

Bosnich saved shots but his distribution, and particularly his kicking, remains a concern.

Having grown accustomed to the authoritative figure of Peter Schmeichel, United are still prone to funnelling the ball backwards into their own penalty area, a tactic that will invite catastrophe until such a time as Bosnich's confidence is fully restored.

United grow in stature to fit the occasion these days and when not repelling Marseille's neat but inadequately paced assaults, they built positively upon the craft and guile of Keane and Paul Scholes.

Even so, Marseille should certainly have moved in front after only seven minutes when Pierre Issa reached a Robert Pires corner only to permit the ball to glance off his forehead.

With Giggs and David Beckham able to suppress their natural instinct to dart down the flanks at every opportunity, United rolled forward. But there were isolated pockets of French resistance and despite the familiar reluctance of Fabrizio Ravanelli to dovetail with any of his colleagues, Marseille were to enjoy the better of what few chances a rather lethargic opening half was to give up.

The best of these openings fell to Pires on the half-hour but having finally found a way through the formidable barrier presented by Jaap Stam and Henning Berg he was denied by Bosnich, who dived away to his right to save quite splendidly.

On a heavy pitch Marseille's football began to hold more promise but by stretching the play, by committing more men forward, they had no option but to weaken their defensive stranglehold.

United might even have gone in front five minutes into a furiously paced second half. Having collected Cole's precise pass Keane was to drive across the face of goal and only fractionally wide of the far post.

Marseille's response was swift, a sweeping and deliberate move that ended with the ball at the feet of Ravanelli but the Italian disappointed once again, his weak shot being comfortably saved by Bosnich.

And then came the breakthrough. With 21 minutes remaining Marseille moved in front. Stephane Dalmat's fine through ball released William Gallas down the centre and he steered a fine, rising drive beyond Bosnich.

Ferguson blamed a costly loss of concentration for his side's defeat. "We lost concentration and we deserved to be punished for it," said Ferguson. "To be honest I thought we defended reasonably well for most of the game and I felt we had plenty in the locker. Once we lost the goal we picked up the pace of the game.

He added: "They (Marseille) are a good side and some of their football was good at times, but for most of the game we held them well."

Marseille: Porato, Blondeau, Gallas, Berizzo, Perez, Issa, Brando (De La Pena 64), Dalmat (Reina 88), Luccin, Pires, Ravanelli (Maurice 74). Subs Not Used: Trevisan, Belmadi, Diawara, Bakayoko. Booked: Perez. Goal: Gallas 69.

Manchester Utd: Bosnich, Irwin, Stam, Berg (Solskjaer 83), Neville, Giggs, Keane, Scholes, Beckham, Cole, Yorke. Subs Not Used: Van Der Gouw, Higginbottom, Clegg, Butt, Cruyff, Greening. Booked: Scholes, Yorke, Beckham.

Referee: H Krug (Germany).