Darren Ferguson insists Preston must improve in front of goal after his side wasted a host of chances before sealing a 2-1 extra-time win at Bradford in the Carling Cup.
Keith Treacy's 109th-minute strike settled the second-round tie in favour of the npower Championship club.
Paul Coutts put Preston ahead with a 25-yard shot after goalkeeper Jon McLaughlin had twice denied Treacy, who also struck the woodwork twice.
That was before Bradford, who knocked out Nottingham Forest in round one, had equalised through Jake Speight with eight minutes remaining.
"We have got to take our chances better," said Ferguson. "We had a lot of shots. We have had many chances in our games this season and we must take a higher percentage of them.
"In the first half we were in complete control of the game - it just took us a little while to get our first goal. In saying that, they played so deep we just had to be patient.
"I thought we would hang on but Bradford equalised, and in extra-time I thought we were the better team."