The Spanish giants hit the post twice, but will now take an away-goal advantage into the second leg.
"This is a positive result for us, but we could have sealed the tie," said Ramos. "We will play the return leg at home before our fans, so we have to go through to the next round.
"We had three very clear chances on goal. This is a good result that gives us the advantage in the second leg.
"We must always be optimistic and dream about winning the tie."