The Saddlers arrived at the clash with the Cobblers on the back of a drab midweek draw with Newport County as the travelling Reds were unable to secure a single shot on target during a pitch and weather affected game in South Wales.
However, on Saturday goals from Josh Gordon and Danny Guthrie had pulled the Saddlers level after seventy-seven minutes of play before substitute Rory Holden opened his account for the season as he sealed the points deep into second-half stoppage time.
Although Clarke was delighted to see his side fight back from being two-down at the break, the manager admitted he got his initial team selection wrong as the visitors were able to dominate much of the opening half of the game.
Speaking to the assembled media, Darrell said; "Credit to the boys for the second-half performance. Albeit I’m very frustrated in myself as well.
"I like to explain my decisions, I picked a team that was robust to match the conditions. I’m very disappointed to give away two sloppy goals which means you’re chasing.
"Credit to the lads that came on and changed the game. What I demand from my team is that character, that never say die attitude. They showed it in abundance there. The frustrating thing for me is I think we gave them a heads up on the two goals.
"We’ve worked on defending crosses in the box, we know Northampton are big, strong and good at what they do. They get good deliveries in and to be fair they could have got the third.
"Frustrated because I picked the wrong team, that’s what happens. It’s easy for people to say that and I get that. When you’re 2-0 down there’s no hiding place. But credit to the boys that came on and the lads that stayed on the pitch to turn it around."