Atletico were put ahead early on three minutes when Sergio Aguero's attempted pass found Maxi Rodriguez by chance, and the latter lashed clinically.

The leveler was netted on 22 minutes when Lisandro outwitted defender Pablo Ibanez, whose silly deadly slip-up enabled the Argentine ace to drive the ball home.

Just before half-time, Diego Forlan saw his poor long-range shot land into the net between the legs of goalkeeper Helton, who was left embarrassed by his gaffe.

Eighteen minutes from time, Lisandro turned in Aly Cissokho's low cross to upset the hosts, whose qualification hopes have been dented.

The second leg takes place at Porto on March 11th.