Russell Slade was left fuming after Cardiff were denied a late penalty in their goalless draw with QPR.
The Bluebirds failed to close the gap on the Sky Bet Championship play-off places after they were held at home.
But that was only after Cardiff were denied what Slade claimed was an "obvious" penalty in the 86th minute when Anthony Pilkington went down under the challenge of Grant Hall.
Referee Stephen Martin waved away furious protests from the Cardiff players and after the game Slade said: "I thought we thoroughly deserved to win.
"There was one great save, a couple of near-misses and an unbelievable penalty shout when he [Pilkington] was wrestled to the ground. It was incredible that we didn't get that.
"I don't usually moan because these decisions even themselves out over the season, but I get upset when you don't get such an obvious decision."
Sean Morrison had a header well saved while Kenneth Zohore saw his late effort cleared off the line as Cardiff were left frustrated.
The goalless draw means they are still five points behind Sheffield Wednesday in the final play-off spot but this was an opportunity missed.
Slade added: "We've said we have to match their [Wednesday's] result and we've done that.
"In one way, we may see that as an opportunity where we lost two points but we're still in there and still fighting.
"We go to Brentford next and need a positive result and we probably need to win all four of our remaining games. It's a big ask but it's not impossible."
Jimmy Floyd Hasselbaink ended his playing career at Cardiff and has now steadied the ship at QPR who have lost just twice in their last 11 games.
But the former Holland international striker admitted his team lacked ambition in attack.
He said: "We controlled the game in the first half and had a lot of possession but I would have liked to see far more penetration. We should have gone for it more and ended our attacks with a shot or a cross instead of keeping the ball for the sake of it.
"Cardiff didn't have a lot to say or couldn't get near to us but I'm not someone who just wants possession. We need to have a purpose and that could have been better.
"But we were dominant with the ball which is refreshing at such a tough place given Cardiff have only lost once at home.
"We knew they would come out in the second half and that we would have difficult moments.
"But we dug in and put our bodies on the line in the last few minutes and showed some real spirit and commitment. So I'm very happy that we kept a clean sheet."