Cobblers boss Keith Curle was delighted with his side's performance during Tuesday's League Cup tie at Swansea City after they led for so long before conceding three late goals.
Matty Warburton's first professional goal had Town on course for a potential cup upset as he rolled into the bottom corner on 61 minutes.
The visitors defended well throughout and maintained their lead for another 30 minutes, but Swansea got themselves out of jail with three late goals.
Andrew Ayew scored twice and George Byers netted the other to send Cobblers out of the competition at the first time of asking.
"For 70, 75 minutes I thought we were very good," said Curle.
"There was a good understanding of the shape, good application and as I said to the players in the changing room, for 75 minutes we were very, very good for where we are and where we want to go to.
"But what you find is, to get better and to improve, you've got to have the mentality of doing the right things at the right times repeatedly. You've got to make the right decisions for 95, 96, 97 minutes.
"But I thought we got the shape exactly right and made them step into the areas we wanted and then won the ball back.
"We gave the ball away too cheaply a few times in the first-half but it was a great experience for the players."