Barcelona have crashed out of the Copa del Rey after suffering defeat to Athletic Bilbao.The game looked as if it would go into extra-time with the scores goalless after 90 minutes.But Sergio Busquets' own-goal in the 93rd minute sent the hosts through and shocked Barca.It was a really poor result for Quique Setién, who lost his second game at Barca since taking charge last month.But he will have many complaints about the manner of his side's loss.

That's because Barca were denied a clear penalty midway through the second half.

Frenkie De Jong made his way into the box after some good interplay down the left-hand side.

But, as he was bearing down on goal, he was charged in the back by Ander Capa.

Watch the full move and foul below:

And a close up of the incident shows just how clear of a foul it was by Capa.

That looks like one of the most blatant penalties you'll see. Capa got himself on the wrong side of his man and just barged De Jong in the back in a desperate attempt to recover.

However, the referee felt otherwise. And VAR wasn't even used to check the incident.

Just baffling. It came back to really hurt Barca too, with Williams' late goal sending them crashing out of the competition.

Setien refused to talk about the penalty after the game.

"I didn't see it from where I was," he said. "I was told it was clear. I won't talk about the referee."

But, despite the result, he admitted he was pleased with his side's performance.

"The result is always the most important thing but the sensations are also important. The team played well today. I think we were the better side," he said, per Sport.

"It's not easy to control the game against Athletic, but I don't think Ter Stegen had a save to make in the whole game.

"In the second half, we had four or five clear chances and their goal's arrived with no time to react. The game went as we wanted in the second half, it's shame we couldn't get ahead because they weren't comfortable."