Swindon manager Richie Wellens claimed his side were made to pay for not taking their chances after losing 1-0 to Cheltenham in their FA Cup first-round replay.
Alex Addai scored the only goal five minutes into the second half after Cheltenham goalkeeper Scott Flinders had saved Michael Doughty’s first-half penalty.
Frustrated Wellens said: “I’m frustrated because we were not at our best, but we didn’t deserve to lose – they have had one shot on target.
“I don’t mind to lose when the opposition have been very good but we’ve hit the post twice and the penalty would have got us off to a great start.
“We paid a price heavily. We didn’t put them away at their place, but also we should have been more ruthless and put away chances.
“We made chances, we moved the ball well, the ball is flying across that six-yard box, we just need someone to take that chance.
“It is a tough one to take. It’s difficult when you’re the better team – we could’ve worked the keeper on a couple more occasions.”
Swindon had enough chances to cruise into the second round and could have taken the lead from the spot after only three minutes.
Doughty saw his penalty saved well by Flinders after Kaiyne Woolery was brought down before Jordan Lyden fired the rebound over the bar from close range.
Swindon came close again just before the half hour when Jerry Yates headed a Diallang Jaiyesimi cross against the foot of far post.
Addai put Cheltenham in front in the 50th minute after collecting the ball down the left before cutting inside and firing a rasping effort low into the right corner.
Swindon were denied by the post again seven minutes later when Doughty struck the woodwork one-on-one with Flinders.
Cheltenham manager Michael Duff said: “We’ve had to ride our luck a little bit, Scott has had to save a penalty in the third minute of the game, but I thought we were excellent.
“After we went 1-0 up, we solidified it a bit and went a little bit deeper so they couldn’t play through us like they did at our place.
“As soon as we scored the goal, we took what we got. I know they hit the post but I can’t remember Scott making any saves.
“People were throwing their bodies on the line, being difficult to beat and being resolute.
“They’re a big club in League Two and they’re top of the league – they are a good team so you are not going to get it all your own way.
“The penalty save is maybe the little bit of luck that we needed. I thought we were much better today.”