Manchester United fell to one of the most embarrassing European defeats in their history as Champions League upstarts Como ran out 4-1 victors on Wednesday to heap pressure on head coach Michael Carrick.

The under-fire Red Devils boss had felt Sunday's purposeful point at rivals Leeds marked a "fresh start" after Lisandro Martínez highlighted the club's shortcomings in a set of stunning interviews last week.

But United instead saw their wretched start to the season hit a new low on Wednesday as Cesc Fabregas' Como punished a display devoid of shape, grit and skill to extend their winless run to a seventh match.

This humbling loss puts Carrick's future under intense scrutiny, with the storm that battered the Stadio Giuseppe Sinigaglia nothing compared to the one brewing at Old Trafford.

United made a nightmare start, just as they did at Atlético Madrid last week, as burgeoning star Nico Paz struck against a side that were shaky out of possession and shapeless with it.

Carrick's side were fortunate to only be a goal behind at the break and their luck soon ran out, with Tasos Douvikas' strike followed by Paz scoring his second and Jacobo Ramón heading home.

Substitute Joshua Zirkzee added a consolation goal on a night that ended with Carrick holding his hands up apologetically in front of those United fans that stayed until the end.

United were without nine players in Italy but Como were also beset by injuries and managed to play bold, joined-up football that had the visitors chasing shadows.

Things could have been different had Diogo Dalot scored inside 90 seconds, but that miss was followed by Fabregas' men scoring a dream opener with two minutes on the clock.

Paz collected a pass on the edge of the box and caught out United by immediately cutting onto his left foot and bending the ball brilliantly past Senne Lammens.

There was little sign of life beyond Harry Maguire's header wide, with United's understandably frustrated following bellowing "attack, attack, attack."

But Como looked most likely to score as Douvikas showed what the presence of an out-and-out striker can do, forcing a save from Lammens and driving over towards the end of the first half.

Carrick reacted by making changes at the break, bringing on Carlos Baleba and Amad Diallo as well as making some tactical tweaks, but just four minutes after the restart Como scored again.

Incisive attacking play cut through the middle of the United team, with Douvikas slamming home from Paz's pass having left Matthijs De Ligt stumbling on the defender's first start in 325 days.

United looked punch drunk and the 57th minute brought Como's third. Baleba saw a pass cut out on the flank by Paz, who darted forward and scored a fine left-footed finish.

Carrick redoubled their efforts and Diallo was denied by Jean Butez during that push, but the damage had already been done.

In fact, the hosts would inflict further harm in the 76th minute when substituteKaiki Bruno crossed for unmarshalled Ramon to head home in front of the raucous Como support.

United's end emptied as their side stumbled on, with Lammens preventing Paz from completing his hat trick.

Substitute Zirkzee scored in stoppage time but there was no disguising what a catastrophic display this was on the shores of Lake Como. Little wonder Carrick felt the need to apologise.