A freak own goal saved Arsenal's bacon as the Gunners rescued a 2-2 draw in the first leg of their Europa League last-16 tie against Sporting Lisbon at the Estadio Jose Alvalade.
A pulsating four-goal contest saw Goncalo Inacio and Paulinho cancel out William Saliba's header, but an outswinging Granit Xhaka cross wound up in the back of the net via Hidemasa Morita to leave everything to play for at the Emirates Stadium next week.
It was a tale of two corners in the first half, as Mikel Arteta's men deservedly turned their plentiful possession into the opening goal in the 22nd minute, as Saliba nodded home from Fabio Vieira's set-piece.
Ruben Amorim's players protested vociferously, as replays showed that Oleksandr Zinchenko had seemingly hauled Matheus Reis to the ground, but the VAR officials saw no reason to disallow the goal.
Despite drawing first blood, Arsenal's rejigged backline were nearly the architects of their own downfalls, falling victim to the intense Sporting press and giving the ball away cheaply on several occasions.
Sporting's relentless pressure led to a corner of their own in the 34th minute, and Inacio broke free to power a header into the back of the net and level the scores thanks to some questionable Gunners decisions.
While Jakub Kiwior inexplicably ducked out of the way as Inacio surged forward behind him, stand-in goalkeeper Matt Turner hesitated and failed to claim the cross into his six-yard box, giving Inacio the easiest of tasks to find the bottom corner.
There were suggestions that Turner had shouted for the ball before backing off - hence Kiwior's evasive action - but the American partially redeemed himself in the 39th minute, keeping out a goal-bound Marcus Edwards strike at full stretch.
With neither side covering themselves in glory from dead-ball situations, Arsenal were inches away from regaining the lead through Xhaka's back-post header, but Antonio Adan just about prevented the ball from going over the line.
Turner would very nearly gift Sporting a goal on a silver platter just before the half-time whistle blew, and it took just three minutes of the second period for Adan to be called into action, making himself big to keep out Gabriel Martinelli's attempted chip following a deft pass from Zinchenko.
Portugal native Vieira had a 20-yard sighter just one minute later, but his attempt flashed just wide, and Arsenal's fast start to the second half paled into insignificance in the 55th minute, as Paulinho put Sporting ahead after Turner had palmed Pedro Goncalves's strike into a dangerous area.
The hosts had their tails up, but Martinelli almost recreated his stunning solo goal against Chelsea in the 59th minute, running nearly the full length of the field and skipping past Adan before Jeremiah St. Juste made a miraculous last-ditch challenge.
A frenetic start to the second half showed no signs of slowing down, as Paulinho blazed wide when one-on-one with Turner in the 61st minute, before Xhaka's attempted cross for Martinelli was deflected into his own net by Morita as Arsenal drew themselves level in unorthodox circumstances.
The pace of the game drastically slowed down in the final 25 minutes, with Adan saving a couple of speculative Saka attempts before the curtain closed on a peculiar contest.
Arsenal now prepare to resume their Premier League title charge away to Fulham on Sunday afternoon, while Sporting host Boavista in Primeira Liga action a few hours later.
