Ramsey scores twice, second a brilliant flick, also hits post
Lacazette also bags brace, including penalty after Ozil fouled
Golovin briefly brings CSKA level with superb free-kick
Three other last-eight ties, inc. Atletico Madrid v Sporting
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Peter: This is what happens when Ozil is left unmarked. He's being given the freedom of North London and using it well!
Liam: Ozil doing Ozil things. He just find people.
Image source, ReutersArsenal 4-1 CSKA Moscow
Ahmed Musa is basically taking on Arsenal on his own at the moment - another top-quality run at the defence, this time he shoots himself and it's saved by Petr Cech. If only his team-mates were as good as him.
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Daniel: Seriously amateurish defending by CSKA... ruthless from Arsenal though, take nothing away
Robin: Never thought with the way this season has been I would be asking this. If 2 players score a hat-trick who gets the match ball? Thought I'd ask just in case.
It looks like the one who scores his third goal first usually gets it...
Arsenal 4-1 CSKA Moscow
Ahmed Musa is causing all kinds of problems for Arsenal's defence - maybe Leicester should have given him more of a chance.
He tears Hector Bellerin to shreds and squares the ball for Alan Dzagoev, who fires woefully over the bar from a good position.
Image source, Getty ImagesArsenal 4-1 CSKA Moscow
Arsenal break at pace again and you can almost sense the relief from CSKA as Jack Wilshere runs into a Russian player and loses the ball.
This could end up as an absolute rout.
Lazio 1-1 Red Bull Salzburg
Lazio have handed Red Bull Salzburg a route back into the game with Dusan Basta giving away a penalty for a flailing arm on Munas Dabbur.
Valon Berisha stepped up and smashed the spot kick down the middle past Thomas Strakosha in goal.
Alexandre Lacazette
Call off the tie. It's all over.
Alexandre Lacazette joins Aaron Ramsey in the two-goal club.
Granit Xhaka plays Mesut Ozil down the left. The German adds another assist to his impressive record as he crosses for Lacazette, who takes a touch and then rifles the ball from 18 yards past CSKA keeper Igor Akinfeev.
Image source, ReutersArsenal 3-1 CSKA Moscow
CSKA's goal was the first direct free-kick Arsenal have conceded in a major European competition since December 2014 (Wesley Sneijder for Galatasaray).
Arsenal 3-1 CSKA Moscow
After CSKA blaze a shot well over, utility man Pontus Wernbloom is booked for a high foot on Shkodran Mustafi.
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Mat: What.....a......goal! This is what happens when you play fast football!! Teams can't cope! Look at Liverpool last night!
Ankur: Lionel Ramsey
Aaron Ramsey
What a goal! I didn't know Aaron Ramsey had that in him.
Mesut Ozil lifts a ball over the top and Ramsey, leaping in the air, sends it over the keeper with a backheel.
That's Ramsey's second.
Image source, ReutersArsenal 2-1 CSKA Moscow
CSKA striker Ahmed Musa slips as he shoots and it's high and wide. It's a much more entertaining game than I was expecting.
Arsenal 2-1 CSKA Moscow
CSKA have a corner now, all the big old men come forward. It's played deep for some reason but Arsenal get the ball and break - before giving the ball away near halfway.
Alexandre Lacazette
Alexandre Lacazette steps up... and sends keeper Igor Akinfeev the wrong way.
That's his second penalty in two games since his return from injury - and Arsenal are ahead again.
Image source, ReutersArsenal 1-1 CSKA Moscow
Mesut Ozil goes past Georgi Schennikov, who tackles him but doesn't make contact with the ball. Definite spot-kick. Even if it took the referee a few seconds to award it.
Image source, PAArsenal 1-1 CSKA Moscow
Arsenal, who would have been hoping not to concede an away goal, have a corner as Alexandre Lacazette's cross is blocked.
The corner comes to naught.
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Mat: Brainless defending costs Arsenal.......again!
Patrick: My GOD that was thick defending. Rightly punished
Laurent Koscielny conceded the free-kick after some terrible Arsenal defending...
Arsenal 1-1 CSKA Moscow
While I was still telling you about that goal, CSKA Moscow should probably be ahead. Ahmed Musa sends an Arsenal defender to the floor with a good piece of skill but then shoots into the side netting.
Aleksandr Golovin
CSKA Moscow are level and it's an absolutely world-class free-kick from Aleksandr Golovin. He steps up just outside the D and curls one right into the top corner. Petr Cech had no chance.
Wow.
Image source, Reuters#bbcfootball or 81111 on text
Abdul: I'm sure this one will stand, what a goal for Ramsey.
Henock: Arsenal playing a flawless game. Beautiful football from Arsenal!
Image source, Rex Features