Champions League: Olympiakos add to United's woes; Dortmund spurred by Lewandowski brace

Manchester United's dwindling hopes of lifting a trophy this season are dangling by a thread after they produced an abject display to lose 2-0 at Olympiakos Piraeus in a Champions League last-16 first leg on Tuesday.

- Champions League: United stunned by Olympiakos; Dortmund thrash Zenit

Alejandro Dominguez opened the scoring with a clever first-half flick and Arsenal loanee Joel Campbell added a sublime second goal to leave United facing a huge task to overturn the deficit in the return match at Old Trafford on March 19.

"That's the worst we've played in Europe. We didn't deserve to get anything," manager David Moyes said.

"I'm surprised, I didn't see that level of performance coming.

"I take responsibility, we have to play better. The players are hurting."

Defeat at the Georgios Karaiskakis Stadium represented yet another body blow in an inauspicious campaign for last season's English Premier League title winners.

United are out of the FA Cup and the League Cup and trail Premier League leaders Chelsea by 15 points with 11 games left to play.

Moyes's men looked sluggish and disjointed against an inexperienced Olympiakos side who are bidding to reach the quarter-finals for only the second time in their history.

It was the first time the Greeks had beaten United in five attempts.

"To beat a great side like United, the way we did, is something very special and I can't hide the joy and pride I feel for my players," said Olympiakos coach Michel.

"We picked the best moment to show Greek football is alive and kicking," added the former Spain and Real Madrid striker.

Moyes opted to start with two wingers, Antonio Valencia and Ashley Young, but neither made an impact in a first half in which runaway the Greek league leaders displayed real energy and hunger.

After a cautious opening from both sides amid ear-splitting noise from an enthusiastic home crowd, the first chance fell to Olympiakos as Dominguez burst through the middle on a solo run only to be denied by a last-ditch tackle from Nemanja Vidic.

Midfielder Tom Cleverley registered United's only effort of note in the first half with a 17th-minute half-volley that sailed high over the bar.

Strike pair Wayne Rooney and Robin van Persie were peripheral figures for the visitors as pot shots on goal from Giannis Maniatis and Hernan Perez lifted the home supporters.

Olympiakos broke the deadlock seven minutes before halftime with a smart piece of improvisation from Argentine forward Dominguez.

Patrice Evra's half-hearted clearance from a corner landed at the feet of Maniatis 25 metres out and his tame, low shot was expertly diverted past keeper David De Gea by Dominguez's flick.

United were punished again for poor defending 10 minutes into the second half.

Campbell, who is likely to feature for Costa Rica against Group D rivals England at the World Cup in Brazil in June, did the damage.

He picked up possession 25 metres out, jinked past midfielder Michael Carrick and sent a curling left-foot shot round defender Rio Ferdinand and into the bottom corner of the net.

Moyes sent on Danny Welbeck and Shinji Kagawa for Valencia and Cleverley but it was more a change in attitude than personnel that was required from United.

Dutch striker Van Persie summed up his team's night with five minutes to go. He received the ball 12 metres out and turned inside a defender before blazing a right-foot shot way over the bar.

Borussia Dortmund's Robert Lewandowski scored twice in a clinical 4-2 win at Zenit St Petersburg who were made to pay for some dreadful defending in their Champions League last 16, first-leg tie on Tuesday.

Zenit offered free tea and pies to the visiting fans at the Petrovsky stadium and their players were equally generous as they repeatedly gifted possession to their Bundesliga opponents.

Dortmund grabbed two goals in the first five minutes through Marco Reus and Henrikh Mkhitaryan after Zenit, looking rusty as they started their first match after a two-month winter break, twice lost possession on the halfway line.

Although the hosts fought back with second-half goals from Oleg Shatov and a Hulk penalty, Lewandowski replied on each occasion, helped by some more mishaps in the Zenit rearguard, as he took his tally in this year's competition to six.

The second leg on March 19 should now be a formality for last season's runners-up against opponents who qualified for the last 16 despite mustering only six points in the group stage and were clearly out of their depth in the knockout phase.

"We were incredibly active and aggressive. It's not easy to do that. The team put in a fantastic performance," Dortmund coach Juergen Klopp told reporters.

"This was close to an optimal performance. We pressed to great effect against a dangerous team."

Disappointed Zenit coach Luciano Spalletti added: "...we conceded the two quick goals. It made a big imprint on the match and as a matter of fact decided the game.

"We made too many ridiculous mistakes and were punished. You can't afford these kind of mistakes at this level against opponents like Borussia. If you do you pay a very high price."

Zenit, forced to close several sections of the stadium because of racist incidents in their group game at Austria Vienna, were quickly in trouble when Yuri Lodygin's goal kick was collected by Dortmund on the halfway line.

Marco Reus burst into the area and, although he stumbled, the ball ran kindly to Mkhitaryan and the Armenian fired the ball past Lodygin.

The Zenit goalkeeper had to pick the ball out of his net again 70 seconds later after Zenit incredibly lost possession on the halfway line again following the restart.

This time, Mkhitaryan burst down the right and found Kevin Grosskreutz who laid the ball off for Reus to score with a clinical first-time finish.

Dortmund continued to pen Zenit back in their own half and Reus curled another shot just wide of the post from the edge of the penalty area.

However, Zenit regrouped after the break and briefly threatened to stage a fightback.

After Lewandowski's powerful effort was turned around the post by Lodygin, the Russians cut the deficit in the 57th minute with a scrambled goal when Shatov fired in from the rebound after Rondon had one effort headed away and then hit the post.

Poland striker Lewandowski restored Dortmund's two-goal advantage four minutes later after combining with compatriot Lukasz Piszczek as Zenit were caught out by a counter-attack down the right.

There was renewed hope for the home side when Hulk pulled another goal back with a controversial penalty in the 69th minute, awarded after Viktor Fayzulin dribbled into the area and collided with Piszczek.

But their hopes were crushed again two minutes later when Anatoliy Tymoshchuk dithered and was dispossessed in his own half by Reus, who slipped the ball through for Lewandowski to score with a low, angled shot.

"It was incredibly important to grab two goals so early. They were completely thrown off by that," Dortmund captain Sebastian Kehl told Sky.

"We stayed compact and made it difficult for them to create chances. We were dominant at the end."