Porto hero Mariano Gonzalez says they made Manchester United look ordinary on Tuesday night.
He said: "You can say they played badly but the credit should go to us, as we made the great stars of Manchester look like they weren't that great.
"They are a motivated squad but it was our strength that made them look fragile. But they will come to Porto to win the second leg. They have shown they can win at any stadium. They will come to score and they will try to attack from the first minute.
"But as always our fans will be very noisy and that will inspire us."