Gelson Martins' 73rd-minute goal helps Olympiacos beat Kairat to record their first win in this season's Champions League.

Olympiacos beat Kairat to record their first win in this season's Champions League and keep alive their hopes of advancing to ...

Arsenal's Leandro Trossard, right, takes a shot during the Champions League opening phase soccer match between Arsenal and Olympiacos at Emirates stadium in London, England.

LONDON (AP) A goalkeeping blunder by David Ospina helped Olympiakos beat Arsenal 3-2 in the Champions League on Tuesday and leave the Gunners in real danger of its first group-stage exit in 16 years.