Ten-man Arsenal have gone into half time 1-0 down to Dinamo Zagreb in their first Champions League Group F match at Stadion Maksimir.
Arsenal took the game to the hosts immediately and were denied an early opener only by a superb save from home goalkeeper Eduardo, who somehow managed to keep Olivier Giroud from heading home Santi Cazorla's corner.
Marko Pjaca gave the Gunners a warning sign just two minutes later when he perhaps should have hit the target rather than firing wide as Dinamo looked to counter.
Giroud was denied by a last-ditch challenge from Jeremy Taravel before Eduardo produced an even better stop to keep out the Frenchman's rebound after the striker had headed Alex Oxlade-Chamberlain's cross against the post.
All of Arsenal's early dominance was in vain, however, when the Croatian champions took the lead on the break midway through the first half as El Arbi Hillel Soudani released Josip Pivaric, and the ball went in off the unfortunate Oxlade-Chamberlain after David Ospina had stopped Pivaric's initial effort.
Arsene Wenger's side lacked cutting edge throughout the first period and things got worse for them just five minutes before the break as their main goal threat was removed when Giroud was shown a second yellow card for a challenge on Ivo Pinto as a disastrous first half came to a close for Arsenal.