Bayer Leverkusen director Rudi Voller believes a poor refereeing performance prevented his side from earning a point at Bayern Munich.
Mats Hummels headed home the winning goal for Bayern, who were three without a win in all competitions, in a 2-1 win at the Allianz Arena.
However, Leverkusen were left aggrieved when two late penalty appeals were waved away in the closing stages - with Javi Martinez seemingly guilty of handball before he later bundled into Aleksandar Dragovic.
And Voller was left frustrated that Leverkusen were not awarded a spot-kick.
"It was a clear red card for Martinez and a very clear penalty," he was quoted as saying by Sport1. "Although we did not score our last [spot-kick], but I would have liked the penalty.
"We were hoping we could get something here, but everyone must play their part, including the referees and linesmen. It's as simple as that.
"Football is not so complicated - sometimes it's quite simple. There are simple things about victory and the game.
"If the penalty is a penalty, then it is a penalty - and [the referee] has to see it."
Leverkusen are ninth in the Bundesliga after the defeat.