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Arsenal boss Mikel Arteta knows home form will be key for his side's Champions League ambitions.

The Gunners have kept a clean sheet in nine of their last 12 home matches in the competition.

"We have the same ambition - to go game by game and try to be better than the opponent, which is very difficult in this competition," Arteta said.

"We want to win as many games as we can. This game is going to be a really difficult one. We know how important the home form is going to be to reach the phase we want to."

Steve Sidwell
Former Chelsea midfielder on TNT at Lotto Park

Eddie Howe will be a happy man but it was all about getting those three points and it was the way the went about it.

Stick around for reaction to that big win for Newcastle, but we will also now be switching focus to the 8pm games.

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Four goals and three points for Newcastle.

A brilliant performance to get their Champions League campaign up and running at the second attempt.

Union must be absolutely sick of Newcastle at this stage.

They're 4-0 up in stoppage time and yet every time they win the ball back, they're flying forward to try and score a a fifth.

Relentless from Eddie Howe's side.

We're into the second of four added minutes. Not long until Newcastle's victory is confirmed.

So nearly a fifth for Newcastle.

Lewis Hall with the cut-back and Sandro Tonali's shot is superbly pushed onto the crossbar by Kjell Scherpen.

The resulting corner comes to nothing.

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Harvey Barnes isn't happy but he is called for a foul on Mathias Rasmussen. It's more for the follow through than the tackle itself.

It doesn't matter too much as Union take the free-kick short and promptly lose possession.

Into the last five minutes but there's no sign of this one petering out just yet.

Union want to give their fans something to cheer while Anthony Gordon is on a hat-trick, so while some Newcastle players might be happy to calmly play this out, he is not.

The former Everton man is driving the visitors forward when he gets the ball.

One last change for Newcastle as Fabian Schar comes on for Kieran Trippier.

Steve Sidwell
Former Chelsea midfielder on TNT at Lotto Park

It all starts from Gordon there doing the dirty work. It's all about detail in the middle of the park to create the chance for Barnes but he just got it in. He will be delighted.

Sofiane Boufal gets the ball out of his feet and lets fly from 25 yards.

Good effort but it's pushed away by the diving Nick Pope.

Alex Howell
BBC Sport football reporter at Emirates Stadium

The Olympiacos fans have basically filled their section and there is still 45 minutes to go until kick-off.

They made a great noise when their goalkeepers came out to start their warm up.

The travelling supporters are really going to lift the atmosphere tonight.

Image source, BBC Sport

Another change for Union before a Newcastle corner.

Louis Patris is on for Anan Khalaili.

Nothing comes from the set piece.

Harvey Barnes almost gets in after a lovely run.

He tries a one-two with Anthony Gordon on the edge of the box but can't quite reach the return pass before the defender.

Sandro Tonali is down briefly after colliding with Mathias Rasmussen.

He is up, gives his thigh a rub and is OK to carry on.

It's all been very stop-start since Newcastle's third goal with various stoppages in play.

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Triple change for Newcastle with Lewis Hall, William Osula and Harvey Barnes all coming on.

Nick Woltemade, Anthony Elanga and Bruno Guimaraes head off, their work for the night is done.

Meanwhile, Sofiane Boufal - who scored Premier League goal of the season in his time at Southampton - is on for Union. Kevin Rodriguez is off.

Anouar Ait El Hadj curls a shot over the bar from 20 yards.

The Union man should problem looked for a pass, he had options left and right with Newcastle's defence exposed.

Not something we've seen very often tonight.