Cardiff manager Dave Jones said conceding a last-minute goal took the shine off an otherwise "fantastic" 4-1 home victory over Derby County.
As the race for promotion looks set to go down to the wire, Jones had demanded a clean sheet from his players to boost his side's goal difference tally.
"That that was the negative on a game that was relatively easy," he said.
"We made it easy because we made the hard yards in the game. The last 15 minutes was the annoying part."
Cardiff missed out on a Championship play-off place on goal difference in the 2008/09 season and Jones stressed that every goal counts in the "business end" of the season.
"We know that better than anybody and that's what I said to the boys," he said.
Jay Bothroyd gave Cardiff the perfect start by scoring from the penalty spot after just seven minutes, ending a 10-match run without a goal for the club's top-scorer.
The England striker took the responsibility off Peter Whittingham, who had missed for a third time this season with his last effort from 12 yards in the 1-0 defeat to Crystal Palace in March.
"I was surprised Jay Bothroyd took the penalty but he is now back on the scoresheet after a long break although I did think Peter Whittingham would take it," said Jones.
Whittingham did manage to add to his season's tally, though, firing home a superb volley to put the home side 4-0 up with more than 20 minutes remaining. Dekel Keinan and Paul Quinn had earlier turned Cardiff's dominance into goals.
The result ended a four-match run without a victory for the Bluebirds, a faltering four weeks that had seen them drop from second place in the Championship to fourth.
"People said he hadn't won in four and now he haven't lost in three," said a defiant Jones. "You can manipulate stats all you want.
"We've worked really hard the last fortnight with the players we've had in. And they've done the business today until the last 15 minutes when the game became too easy and we went flicky-tricky and slowed it down.
"That was the only disappointing thing in a fantastic day for us. Everybody worked their socks off and has their rewards for that. But you've got to learn your lessons and a clean sheet would've been nice."
The victory gives Cardiff a six-point cushion inside the play-off places, and keeps them within four points of Noriwch City, who occupy the final automatic promotion place in second.
And Jones took a swipe at the critics who had suggested the recent poor run of form showed the players were struggling to cope with the end-of-season pressure.
"I've always had faith in my players," said Jones, who has been in charge of Cardiff since 2005.
"The outside influences are what we've got to ignore. I've always maintained that all these experts that sit around the table and write in the papers and go on messageboards - that's great, it's fantastic to be an expert.
"But you've got to be in the job. I've managed over 700 games in the football world and played another 300-odd and coached another 500 or 600 games.
"Everybody will think they know better than you. That's the way of life sometimes and you've just got to get on with it."