Aaron Ramsey and Alexandre Lacazette each scored twice as Mesut Ozil put on a Europa League masterclass to overwhelm CSKA Moscow and all but book Arsenal's place in the semifinals.
Arsene Wenger knows winning this competition is the only realistic way his side can get back into the Champions League as they sit 13 points adrift of the Premier League's top four.
He named his strongest side, with Petr Cech returning in goal, and they showed far too much for their Russian visitors with first-half braces for Ramsey and Lacazette sealing a comfortable 4-1 win ahead of the return leg.
Reported Arsenal target Aleksandr Golovin had equalised for Moscow with a stunning free kick but Viktor Goncharenko's side were guilty of spurning several other decent chances and have it all to do in a week's time.
Henrikh Mkhitaryan went close to an early goal but could only hit the side-netting following a smart pass from Ozil -- who would go on to run the game.
The Germany international was involved again soon after, exchanging passes with Ramsey before the Wales international tucked home -- only for the flag to be raised against Ozil earlier in the move.
Igor Akinfeev, the CSKA captain, was the first goalkeeper to leave the new Emirates Stadium with a clean sheet back in 2006 and had the same three defenders -- Sergei Ignashevich and the Berezutski twins Aleksei and Vasili -- in front of him here.
But even though the quartet remain at the heart of their side, they were soon breached this time around, Ramsey slotting home from Hector Bellerin's low cross at the end of a slick move that had the visitors' back three -- at a combined age of 108 -- tied in knots.
Moscow equalised just six minutes later, Golovin curling home a perfect free kick after he was fouled by Laurent Koscielny.
Arsenal regained their composure lost having conceded the equaliser and were soon back in front as Ozil was tripped in the penalty area by Georgi Schennikov.
Lacazette marked his first start since January by scoring the resulting penalty before Ramsey increased the lead with a moment of brilliance -- deftly lifting Ozil's perfectly-weighted pass over Akinfeev to put Arsenal in control of the tie.
The fit-again Lacazette had missed a great headed chance just before that strike but added his own second effort of the night with a well-taken low finish to further push Wenger's men into the semi-finals.
Mkhitaryan should have added a fifth shortly after the restart but fluffed his lines after another wonderful pass from Ozil.
The Armenia international then drew a smart save out of Akinfeev, with Ramsey blazing the rebound over as he went in search of a second hat trick of the season.
Mkhitaryan limped out of the contest to be replaced by Alex Iwobi in a rare sour moment for Wenger, who will take a lot of positives from a strong attacking display.
CSKA were wasteful all evening and had a goal chalked out for offside as Alan Dzagoev headed in after Cech blocked Pontus Wernbloom's shot.
Lacazette then passed up his hat trick opportunity as he skewed a shot wide from just a couple of yards out having been picked out by Iwobi, his last chance to earn the match ball before he was replaced by Danny Welbeck.
Ramsey hit the post as he too could not earn a memorable hat trick before Akinfeev did well to keep out Welbeck's close-range effort.
The game came to a close with Arsenal holding a strong lead heading to Moscow but with both sides thinking they should have scored more goals in what proved to be an end-to-end opening leg.