Athletic Bilbao coach Ernesto Valverde admits their performance wasn't good enough for defeat to Celta Vigo on Sunday.
Athletic had chances to score, including an Alex Berenguer volley which hit the post, but it was an Iago Aspas strike in the 70th minute which proved decisive.
"There have been games where we deserved more, but this was not the case today, even if Celta weren't absolutely superior," Valverde said after the match.
"If we want to aspire to be higher up the league, we have to improve."
The gaffer was particularly displeased with Los Rojiblancos' performance after the break, saying they "didn't dominate like in the first half".
He added: "We weren't good in the second half. It's not that we were really struggling, but we weren't comfortable. In the first half we dominated and were more dangerous.
"We had a couple more chances apart from the shot which hit the post. If we had been a bit sharper, we could've hurt them. The reality is that in the second half we didn't create enough. They were strong in the duels and we weren't as strong as we wanted to be."