Arsenal qualified from the Europa League group stage despite being held to a 0-0 home draw by Red Star Belgrade, with rivals BATE Borisov being thrashed 5-2 in Cologne.
The Gunners were under pressure early on when Red Star's Guelor Kanga found Nemanja Radonjic, but he was unable to pick out a colleague with a low cross from the left.
And there were more home jitters moments later when goalkeeper Matthew Macey scuffed an attempted clearance but Red Star failed to take advantage.
The home side mustered a good chance after 11 minutes when Ainsley Maitland-Niles found Olivier Giroud, whose strike was saved by Milan Borjan.
But the game was shaping up to be a scrappy affair, with passes from both sides going astray and Giroud stumbling in a promising position and seeing his attempted cross roll harmlessly through to Borjan.
After 31 minutes, Arsenal had another opportunity as Francis Coquelin won the ball and set off towards the Red Star area, only to ignore the unmarked Jack Wilshere to his left and then lose possession.
Giroud stabbed an angled shot too close to Borjan as the goalkeeper came out to block, and seconds later Slavoljub Srnic saw his effort from 20 yards tipped over by Macey at the other end.
From the resulting corner after 36 minutes, Macey touched a fine header from Vujadin Savic onto the crossbar and away.
But Red Star were growing in confidence and threatened again as Srnic and Kanga linked but the former saw his attempted pass into the area intercepted.
They should have taken the lead when Richmond Boakye surged through following a fine counter-attack but, with only Macey to beat, bent his attempt wide.
Giroud blasted over from 25 yards as the second half began with Arsenal trying to up the pace, and then the visitors' Srnic sent an angled shot too close to Macey.
Back came Arsenal, and Theo Walcott got down the right to arrow in a dangerous cross that was heading for Giroud before a visiting defender got a crucial touch.
On the hour, Wilshere appealed in vain for a penalty when he went down under a challenge from Nemanja Radonjic, and minutes later his dinked shot was brilliantly hooked off the line by Damien Le Tallec.
With a little over 20 minutes remaining, Arsenal manager Arsene Wenger brought on Eddie Nketiah, whose two goals won the Carabao Cup tie against Norwich City last week, for Joseph Willock.
Wilshere arrowed a cross towards Walcott, who got plenty of power on his header but could not steer it inside the far post, but Arsenal's frustration began to show as the clock ticked towards the final 10 minutes.
Walcott missed his kick after good work between Giroud and Elneny had given him a sight of goal some eight yards out, but Red Star fashioned another good chance for Boakye, who again failed to even hit the target from a promising position.
Nketiah's cross was headed down by Giroud late on, but Red Star cleared and four minutes of added time passed without incident.