Two goals from Sam Hoskins had the Cobblers on course for all three points with 11 minutes remaining, but U’s substitute Frank Nouble out-muscled a tired-looking Tyler Magloire to set up Noah Chilvers to level for a second time.
Magloire was making his second debut for the club having only rejoined permanently two days earlier and his lack of match fitness told in the second-half. Shortly after the goal he was replaced by Harvey Lintott.
"I think it was clear to see that his condition at the moment isn't where we want it to be and it isn't where he probably wants it to be either,” said Brady.
"I thought he was brilliant for 70 minutes and it was probably my fault because I kept him on longer than I should have done and I'll take the second goal on the chin – I'll hold my hands up to that.
"I probably should have made the change earlier but for Tyler to deliver what he did today given the minimal amount of minutes he's had, I'm just really pleased for him.”
Fortunately, Ryan Haynes came off the bench to score a dramatic winning goal in the dying minutes, although Town still needed Lee Burge to make a terrific save from Chilvers in stoppage-time to preserve the points. Fellow debutant Danny Hylton also played his part with some superb work to set up Hoskins for the opener earlier on.
"Danny used all of his experience today,” Brady added. “Some of his touches were sublime and he did really well. I thought it was very interesting that Sam scored twice and set another up and didn't get man of the match. I think our fans are just trying to welcome Danny to Northampton!
"It's a match-winning save from Burgey at the end. A lot of goalkeepers might have gone to the floor but he stood up and made the save and that's what we brought him in for - I'm really pleased for him.”