A Robin van Persie hat-trick against Olympiacos gave Manchester United manager David Moyes a stay of execution and prevented a possible fans revolt.

With confidence at a low ebb following the demoralising defeat by fierce rivals Liverpool, Moyes knew that his charges had a duty to deliver an improved performance to ease the mounting pressure.

And it was van Persie who opened the scoring from the penalty spot midway through the first-half before doubling his side's lead just before the break.

Seven minutes after the restart the Dutchman scored a sweetly struck free-kick to become the fifth Manchester United player in the club's history to score a Champions League hat-trick.

"I'm not feeling any pressure from inside the club," said Moyes after the game.

"It's coming from you people (the press). We know the job we have to do. It's probably bigger than what I thought when I first came to the club.

"There are stories of this player falling out, or that one falling out, but it's rubbish. People are looking for reasons why we are not doing well, but it is only because we have not been playing well."

Olympiacos went into the game chasing their first and appearance in the Champions League last eight since 1999.

United needed to claw back a two-goal deficit from the first leg. The last time this had happened was 30 years ago when Bryan Robson inspired the team to a 3-0 win over a Barcelona side that included Diego Maradona.

And the Greeks knew that that just one goal would almost certainly put the Reds out of the competition.

Hernan Perez had the best opportunity in the opening stage to put the visitors ahead but missed from eight yards out after some good work by on-loan Arsenal man Joel Campbell in the buildup.

But it was van Persie who settled the nerves of the Old Trafford faithful when he slotted the ball home with 25 minutes on the clock after being bundled over in the area by Jose Holebas.

Coincidentally, the goal came at exactly the same time that Robson had put United ahead against Barcelona in 1984.

David De Gea kept the tie alive with a superb double save from David Fuster and Alejandro Dominguez just moments before van Persie scored United's second in first half-stoppage time.

Andf the other side of the break United claimed the third goal, van Persie wrapping up his hat-trick with a left-foot free-kick from 20 yards that left Olympiacos keeper Roberto a mere spectator.