PSV Eindhoven coach Phillip Cocu warned Champions League rivals Atletico Madrid the tie is far from over after a goalless draw in Holland.
The Dutch champions played the final quarter of the last-16 tie with 10 men as Gaston Pereiro was sent off after 68 minutes for picking up two yellow cards.
Atletico spent the rest of the game camped in the PSV half, but the Dutch champions held firm and Cocu feels that defiance could prove crucial in the Vicente Calderon return next month.
"I am very pleased with the efforts of the team, 0-0 is a good result," Cocu said at his post-match press conference.
"I have previously indicated that this is a good foundation.
"Despite the red card, we did very well with 10 against 11.
"We will try to score in Madrid and with 1-1 we will go into the quarters.
"We have shown that we can make at least one goal in many matches.
"It will be difficult away against a very good team, but we will fight and have our chances."
Cocu felt Pereiro should not have been sent off for his second challenge on Atleti defender Diego Godin.
"The second was not a yellow card," said Cocu. "Just call it a cunning opponent.
"That is the experience they have, it is a lesson for us.
"But I am very pleased with the way my team has played after the (red card) of Gaston."
Atletico have built a reputation as one of the finest defensive units in European football under Diego Simeone.
But the jury remains out whether they have the offensive power to beat Barcelona, Bayern Munich and city rivals Real, and their failure to breach the defence of 10-man PSV will no doubt raise question marks against Atletico's ability to win the Champions League.
Simeone, however, was keen to praise the performance of PSV goalkeeper Jeroen Zoet rather than focus on his side's failings in front of goal.
"We had a lot of chances to score but we ran into a very good goalkeeper," Simeone said.
"The important thing is to dominate and the only thing that was missing tonight was a goal.
"We've had great opportunities...and after the red card I was convinced that we were going to score that goal.
"Unfortunately it did not work out but I am happy with the way we played and the commitment of my players was outstanding."
Asked about the second leg in the Spanish capital on March 15, Simeone said: "That's the beauty of football.
"PSV are a good team, one that can hurt us on the counter and now has the benefit of one goal counting double.
"But the stadium will stand behind us. I have a good feeling about this match."