The Eredivisie side were held by their Polish counterparts at the Stadion Galgenwaard.
Ten Hag felt the stalemate was a good home result against a strong opposition with plenty of European experience.
He told NOS: “I thought we played well tonight. A very mature performance against an opponent that has already played 4 times in Europe this season.
”0-0 at home in Europe is a good result although we did not bring enough attacking wise tonight and we must improve and become more dangerous in that respect. I thought we missed Simon Makienok tonight.
”When we drew 0-0 at home to Valletta in the previous round people said it was a bad result. I know that we must continue to develop as a team and a squad. I thought that considering where we are in our preparation for the new season we did well to match Lech Poznan tonight.”
He added: “Lech Poznan are a great opponent and they have a budget that is much higher than ours. We have a good squad with a lot of potential and we must continue to develop I am confident we will be able to do that. Looking ahead to next week I believe we have a strong chance to progress into the next round of Europa League.”