Substitute Marco Arnautovic grabbed a late winner as Inter extended their winning streak this year to nine games.
The Italian giants look a huge threat in this year's Champions League. The former Stoke and West Ham star had squandered a hattrick of great chances as he lifted the game after the break.
Arnautovic, 34, finally powered home in the 79th minute, blasting home the rebound after Lautaro Martinez borke clear and forced Jan Oblak to save with his legs. Inter are in the driving seat now for the second leg against the Spaniards who didn’t offer nearly enough in attack.
Inter are in form this season and have lost only once, in September to Sassuolo. Beating Juventus and Roma recently has left them nine points clear at the top of Serie A giving scope for concentrating on the Champions League.
Arnautovic made amends for scooping over from seven yards out after opening the defence with an exchange with Lautaro Martinez. Rapper Kanye West cheered the goal from the touchline seats. Noise and songs from the Curva Nord terrace at the San Siro has featured on West’s latest album.
It was tense. The first shot on target came after 36 minutes, and Lautaro Martinez twice went close, especially when sent on goal by Marcus Thuram, and with a header saved in the 78th minute.
Inter boss Simone Inzaghi dominated shots as they look to go one better than losing finalists against Manchester City last season. Inzaghi knows Atletico boss Diego Simeone inside out having been team mates at Roma, winning Serie A in a trophy-laden era under Sven Goran Eriksson. This was their first meeting as coaches.