Goals from Hakim Ziyech, David Neres, Dusan Tadic and Lasse Schone halted the Blancos’ dominance in the Champions League to give the Dutch outfit a memorable night at the Santiago Bernabeu.
Ajax progressed to the quarter-finals with a 5-3 aggregate win and Onana, still basking in the euphoria, disclosed how the team celebrated the triumph with training session called off the following day.
“Actually, it was a normal celebration with a lot of happiness. We went to the hotel happy and celebrated there. I was happy and with my family," Onana told MARCA.
“Then we went back to Amsterdam on Wednesday morning and training was planned, but it got cancelled.
"The fourth goal made me realise it was a reality, that we were eliminating Real Madrid at home. It will take a long time to forget it."
A 2-1 deficit in the first leg was not enough to deter the Sons of Gods from believing and he disclosed that the team were inspired by their performance in Amsterdam.
“We came from Amsterdam with very clear ideas. We were calm because we knew it was complicated, but we had a chance," he continued.
“Our football in the first leg allowed us to dream and I wasn't surprised at how we responded. We each went for a walk on our own in the morning without any pressure. We felt very calm and went out to win."
On Sunday, the Cameroon international kept a clean sheet in Ajax’s 4-0 win over Fortuna Sittard as Erik ten Hag’s side closed the gap on the Eredivisie leaders PSV to five points, and with a game at hand.