Dean Saunders, the Chesterfield manager, was adamant his team had been unfortunate to lose at Bramall Lane.
Two goals from Che Adams condemned the visitors to a second straight defeat after being knocked out of the Capital One Cup by Carlisle on Tuesday evening.
But Saunders, insisting Chesterfield had “dominated” Sheffield United, said: “There are not many teams who will come here and dominate, like we did, from start to finish. I can’t complain about the way we are playing but we’ve got to turn those performances into wins, and sometimes you are better off being lucky than being good.
“This was one of those games where you take the performance and accept that you didn’t get what you deserved. That, for me, is what happened out there.”
Although Chesterfield enjoyed the majority of possession, Sheffield United unleashed more shots on target, with Adams pouncing at the start of each half.
Despite his sense of grievance about the result, Saunders conceded: “We knew they were going to be counter-attacking. You can’t give goals like that away at the start of each half because that just kills you.
“There was some sloppy defending and, for the second goal, we missed about three tackles. You can’t do that but, going the other way, I thought we were excellent.
“I was pleased with nearly all of them. A couple struggled but nearly all of them played well.”
Sam Hird, the Chesterfield defender, told The Star that going to extra time at Brunton Park in midweek had taken its toll on Saunders’ squad but acknowledged they had been careless at both ends of the pitch.
“It was an open game and, in the last 20 minutes, we probably got a little bit tired after Tuesday,” he said. “But we’re a fit side and we’ll go again. I thought the United goalkeeper had a good game but we just needed to tidy up around both areas.”