Arnautovic had missed several big chances earlier in the second half.

He headed over the bar as well as firing over with the goal gaping.

Former Stoke and West Ham forward Arnautovic replaced Marcus Thuram, who was injured just before the break.

The hosts - last season's Champions League runners-up - had the best chances of the match, with Martinez denied twice when Oblak was in the right place to save his headers.

Alvaro Morata came on as a second-half substitute after recovering from a knee injury, but he was unable to make a significant impact on proceedings for Atletico in Diego Simeone's 100th Champions League match as a manager.

Inter goalkeeper Yann Sommer did not have a save to make and kept his 21st clean sheet in all competitions this season.

Simone Inzaghi's side are nine points clear at the top of Serie A and their last defeat in all competitions came on 20 December against Bologna in the Coppa Italia.

Atletico host the second leg at Civitas Metropolitano on 13 March.