Town are still in the bottom three on goal difference after their former striker Jordan Rhodes struck in the 36th minute.
"We kept him fairly quiet but he's popped up with a poacher's goal and settled it," said Robins.
"It's disappointing from our perspective. You know Jordan's a poacher and comes alive in the box.
"He's always a threat and it just happens that we switched off from a set play and he's capitalised on it."
Town's own specialist poacher, Jermaine Beckford, came off the bench to draw a magnificent save from Grzegorz Sandomierski and Robins pointed to that as a pivotal moment.
"The keeper's made a few good saves. He's made a terrific save from Jermaine Beckford and kept them at 1-0," he added.
"There was very little between the two teams. They attacked us pretty well in the first 20 minutes and then we managed to get out of our half and try and attack them.
"In all fairness we've not done enough as a team to try and take anything from it but I still feel disappointed because we could have done.
"We have three games left in order to pick up enough points to survive. It'll go down to the wire no doubt."
- Jermaine Beckford
- Jordan Rhodes