By ESPNSTAR.com staff
Ibai Gomez's goal 10 minutes from time looked to have secured a draw for last season's beaten finalists at the Stade Gerland but Jimmy Briand came up with a late winner five minutes later to secure the win for Lyon.
Bielsa felt that the result was harsh on his side and went against the balance of play.
"We had 85 minutes of domination but we suffered a bad five minutes and that cost us the match," the former Argentina boss said at the post-match press conference.
"Our equaliser had more of an effect on Lyon than it did on us and that is hard to understand.
"We could not defend well because we were disorganised and that's why we didn't win. Maybe a bit more aggression would have put the game in our favour."
With only a point from their first three games, Bilbao look like they are on their way out of the competition but Bielsa is still optimistic that they can make it out of the group stage.
"After obtaining a single point out of nine, we can't be optimistic. But we need to win our next three matches so we can't give up now," he concluded.