"The penalty was fair and I think there was a contact. (But) in case of the first Costa goal there was a fall against Pepe, it's absolutely clear," Santos said post-match.

Portugal captain Ronaldo scored the opening goal after four minutes as he converted a penalty. Diego Costa leveled in the 25th minute with a right-footed finish, though he was alleged to have fouled Pepe in the build-up.

Ronaldo scored his second just before half time. Costa equalized for a second time in the 55th minute. Three minutes later defender Nacho gave Spain the lead with a stunning strike from distance.

Portugal's captain completed his first World Cup hat-trick in the 88th minute as he curled a free-kick over the wall to earn his side a deserved draw.

Portugal will next face Morocco in Moscow on June 20 before taking on Iran in Saransk on June 25.