Viewers of the new Cristiano Ronaldo interview with Piers Morgan on ITV on Tuesday night were left emotional, as the football legend broke down in tears.

The sport star opened up about the loss of his father when he was 20 years old, and was shown a clip of his dad, Jose Dinis Aveiro, discussing his son's growing success.

Jose was an alcoholic, and he died of liver failure at the age of 52 in 2005 before his son's career really took off.

During his interview with Piers, Ronaldo was shown a video clip of his father talking about his football career that he'd never seen before.

Cristiano Ronaldo broke down during Piers Morgan interview (
Image:
ITV)

The star broke down in tears over the clip, admitting it was "unbelievable",

He said: "I never saw the video. I never saw that video. Unbelievable.

"I think the interview would be funny, but I didn't expect to cry. But I never saw these images. I don't know where you... I have to have these images to show my family.

Ronaldo with his father (left) and family
Ronaldo was left emotional about the clip of his dad (
Image:
ITV)

"But I really don't know my father 100 per cent. He was a drunk person. I never spoke with him, like a normal conversation. It was hard."

Viewers took to Twitter over the moving scenes, with many of them crying as they watched Ronaldo wiping away his tears.

One fan said: "I'm not crying..... Okay, I'm crying."

Viewers were in tears during the interview (
Image:
ITV)

Another tweeted: "I have tears in my eyes the whole time. Never was a Ronaldo fan but after tonight I see him much differently."

A third commented: "I’m not crying at the #RonaldoMeetsPiers documentary. You are x."

This was echoed by a fourth viewer who said: " #RonaldoMeetsPiers is so emotional! What an amazing man."