Gonzalo Garcia fired Real ahead before Ruben Neves beat Courtois from the penalty spot. Bono then saved Fede Valverde's penalty to keep the scores level.
Courtois later said: “We played too slowly in the first half and they looked the more likely.
"Then we got the goal and then gave away a silly penalty that levelled it up. In the second half we fixed things we needed to and looked a bit quicker, more agile."
Valverde penalty a shame
“We looked dangerous but it wasn't to be. It's a shame to miss the penalty, but if we keep up the way we did things in the second half, that will surely help us in the upcoming games. We were better in the second half and that's the line we have to follow."
On the debuts for Trent Alexander-Arnold and Dean Huijsen, Courtois continued: “It's our first match together and it's not easy, but they did a good job and if there are things to work on, we'll look at that in the videos. It was a decent first game for them."
On Bono's penalty save, the Belgian added: “Fede has a fierce shot on him. The goalkeeper went early and that's how he stopped it. It's a shame but Fede has to keep his head up and move on."