Alexis Sanchez scored in the second half to help Arsenal salvage a 1-1 draw at Paris Saint-Germain, who were left to rue multiple missed chances after scoring in the first minute of their Champions League opener.
It took only 42 seconds for Edinson Cavani to head the French champions in front, but the Uruguayan missed three more clear opportunities before Sanchez's 77th-minute equaliser.
Arsene Wenger made two notable omissions from the Arsenal lineup, choosing to start David Ospina over Petr Cech in goal while also leaving out marquee summer signing Granit Xhaka.
The decisions were called into question immediately when Angel Di Maria picked out Serge Aurier with a long pass, and the full-back crossed to Cavani for a flicked header inside the far post.
It could have been worse for the Gunners were it not for a superb block by Laurent Koscielny. His defensive partner Shkodran Mustafi gifted possession to the hosts, who cut through their opponents courtesy of superb touches from Cavani and Di Maria, but Adrien Rabiot saw his effort stopped by Koscielny.
Di Maria threatened Ospina's goal again in the 13th minute with an attempt directly from a corner, but the keeper was able to tip over his bar.
PSG controlled much of the early play and Cavani nearly made the Gunners pay again on 34 minutes when Nacho Monreal's poor clearance fell right to the striker, who rounded Ospina but hurried his shot and fired wide.
And Cavanid, looking to star in a PSG side which lost talisman Zlatan Ibrahimovic in the summer, was again lamenting a missed chance just before the break when he gathered a Di Maria pass behind the Arsenal back line, only to lose his footing.
Arsenal were more composed after half-time but had trouble finding a way past PSG defenders Marquinhos and Thiago Silva and could not put a shot on target.
Soon after the hour mark, Sanchez played in Alex Oxlade-Chamberlain, but the winger scuffed his shot and was immediately replaced by Olivier Giroud.
Cavani was in again on 71 minutes but Ospina rush rushed off his line to smother his shot. Moments later, Di Maria had a clear shot at goal, but Ospina stretched to tip his volley over the bar.
Wenger responded by bringing on Xhaka for Francis Coquelin, and Arsenal responded with the equaliser six minutes later.
Ozil played a pass into the box to an open Alex Iwobi, whose hard shot -- Arsenal's first on target of the game -- was saved by Alphonse Areola, but it came right back out for Sanchez to score inside the near post.
Cavani found himself in on goal again in the 81st minute, and this time Ospina did well to take the ball off his feet.
Arsenal had their best chance to steal a winner moments later, but Areola got down in time to push aside Iwobi's shot.
There would be no more goals, but there was some late drama as Giroud and Marco Verratti came together in stoppage time and both received their second yellow cards -- ruling them out of Matchday 2.
Arsenal had to defend one last corner with 10 men, and Marquinhos came inches of heading in a winner for PSG at the far post.