The Gunners profited from the misfortune of Maxence Lacroix.
Arsenal will face Chelsea in the semi-finals of the EFL Cup after overcoming Crystal Palace on penalties following a 1-1 draw in normal time.
The Gunners dominated in the first half of the only remaining quarter-final tie, but found Palace goalkeeper Walter Benitez in superb form.
Despite Palace improving markedly in the second half, Arsenal finally broke them down in the 80th minute when Maxence Lacroix inadvertently put through his own net from a corner.
Marc Guehi briefly spared his blushes when he levelled in the fifth minute of stoppage time.
Yet it more misfortune would befall Lacroix as he was the only player among 16 penalty takers to se his spot-kick saved, Kepa Arrizabalaga springing to his right to send Arsenal into a two-leg tie with his former club.
Benitez frustrates Arsenal
The tone was set for the first half when Noni Madueke surged through on goal in the third minute, only to shoot straight at Walter Benitez, who blocked an effort from the same player 20 minutes later as Arsenal continued to dominate.
Benitez then produced a stunning low stop down to his left to keep out Gabriel Jesus’ header, and his reflexes came to the rescue as he thwarted Madueke again, parrying his far-post strike, with Jurrien Timber’s header over shortly before half-time summing up a frustrating half for the Gunners.
Palace were markedly more comfortable in defence after the interval, though it was not until Adam Wharton dragged wide from long range just shy of the hour mark that they delivered a reminder of their attacking threat.
Lacroix’s evening to forget
The visitors suffered a setback when defender Chris Richards was forced off with an injury following a lengthy delay and, following more two more opportunities that went begging for Jesus, Arsenal took thee lead when a scramble at a corner led to Lacroix prodding past his own goalkeeper.
Yet the stoppage for the Richards injury gave Palace nine minutes of additional time in which to redress the balance, and Guehi did so as he turned through Kepa’s legs after Jefferson Lerma’s knockdown.
Benitez produced more heroics to prevent Declan Rice from winning it at the death, yet the Palace goalkeeper was unable to get close to any Arsenal penalty in a shootout of a remarkably high standard, and Lacroix’s nightmare evening was capped off when he failed to display the same composure of the previous 15 takers.
Beaten in the semi-finals of last season’s EFL Cup by eventual winners Newcastle United, Arsenal have unfinished business in this competition, but will need to be more clinical if they are to see off Chelsea and book a date at Wembley in March.