Unai Emery lauded Villarreal's "almost perfect" performance against Bayern Munich but recognised their 1-0 first-leg advantage was not enough.
Villarreal edged Bayern in the home leg of their Champions League quarter-final, although the margin of victory could have been wider.
After Arnaut Danjuma's early opener, Francis Coquelin had an effort ruled out for offside and Gerard Moreno struck the post.
At the other end, Bayern did not muster a shot on target until the 59th minute; prior to this match, their first such effort had arrived by the 12th minute on average this season.
Despite winning, the scoreline was of concern to Emery – even if Bayern have lost their past five ties in which they were beaten in the first leg, including four against Spanish teams.
"We are here to try to compete and reach the semi-finals," said Emery after Villarreal's first home knockout win in the competition since April 2006.
"We are against the favourites, against a team that hadn't lost, but if we play an almost perfect game like today, we can beat them. If it had been perfect, we would have beaten them by more.
"We have to play another 90 minutes and find continuity. We are not going to dwell on how well we played, that we have won and that we have competed and been better against Bayern.
"We have to be demanding and, at the same time, as the professionals that we are, we want to go one step further. And those steps we are taking do not stop.
"We are going to try to play a 90-minute game, with what it will demand, with what it will require, with the difficulty that we will find more than today, in order to overcome them.
"In 90 minutes today, I'm satisfied that the fans have experienced a historic moment by playing a quarter-final against Bayern Munich, that they have experienced it before and repeated it again and that we played a good game and won, but there are still the second 90 minutes.
"It's part of the game that you have a second goal that is offside, it's part of the game that they have chances and you stop them, it's part of the game that you score a goal, it's part of the game that you have chances and don't score them.
"You cannot think about what has happened and what could have happened. The result is 1-0. It is a good result but logically insufficient. The difficulty there will be greater.
"They are the favourites, they are a great team. It's not normal for them to lose, but they do lose from time to time – even by more goals, rarely, very rarely. Mostly, they win by many goals. We can be happy but at the same time cautious."
He added: "We have 90 minutes left and I want to beat Bayern Munich. Knowing that it is very difficult, I want to do it and I want to work for it.
"And if I don't beat them, I'm not going to be satisfied, I'm going to be frustrated, regardless of whether we played a good game [in the first leg]."