Lady GaGa performed 'Monster' for the first time in eight years at the opening night of 'The Chromatica Ball'.

The pop megastar kicked off her delayed jaunt in support of her 2020 LP 'Chromatica' at the Merkur Spiel-Arena in Düsseldorf, Germany on Sunday night (17.07.22), and her Little Monsters were in for a treat.

The 'House of Gucci' actress not only performed nine songs from the Grammy-winning album, including ‘Stupid Love’, ‘Rain On Me’ and ‘911' and 'Sour Candy', but she also dusted off her 2009 hit that she hasn't performed live since April 2014.

The 20-song setlist also included fan-favourites 'Bad Romance', 'Just Dance', 'Poker Face' and 'Born This Way', as well as 'Shallow' and 'Always Remember Us This Way' from 'A Star is Born'.

The evening ended with Gaga's epic 'Top Gun: Maverick' soundtrack 'Hold My Hand'.

Ahead of the show, Gaga shared that she is "more pain-free" than she has been in ages.

The 36-year-old singer-and-actress suffers from fibromyalgia - a chronic condition that causes widespread pain and extreme tiredness - and took to social media to thank fans for their support.

In the clip, she said: "I want to really thank you for sticking it out with me, and loving me through all the different iterations of my artistry, as well as me as a person. I feel more clear today than I have in a long time, and more pain-free than I have in ages."

The 'Poker Face' hitmaker - whose real name is Stefani Germanotta - said the tour will be a "healing" experience because she is finally able to dance and "tell the story" that she wanted to.

She continued: "Being free of pain on stage is a real healing experience because I’m able to dance and sing and enjoy the audience, enjoy the show…and really tell a story. I just want to thank you. I’m going to thank you in another way, and it’s through this performance. And it will be through every performance. I don’t know that I’ve been as speechless as I am today, knowing what we’re about to do."

Back in 2020, Gaga explained that as a result of the condition, her "whole body" was in pain but was receiving "mental health therapy" as a form of treatment.

She said: "Fibromyalgia is essentially a chronic pain condition that makes your body hurt through your brain. Now, someone that might be watching this that has it might be saying, don't tell me that my fibromyalgia is in my head because my whole body hurts. Even sitting here with you today, I'm in head-to-toe pain. But what's interesting about it is that I've found through neuropsychic research and my relationship with my doctors that fibromyalgia can be treated through mental health therapy. And mental health is a medical condition. It should be treated as a medical condition. It should not be ignored."

Following its opening night in Dusseldorf on Sunday, 'The Chromatica Ball' is set to visit Stockholm, Paris, London, and a slew of US states before wrapping in Miami, Florida in mid-September.

Lady Gaga's Merkur Spiel-Arena setlist:

1. ‘Bad Romance’

2. ‘Just Dance’

3. ‘Poker Face’

4. ‘Alice’

5. ‘Replay’

6. ‘Monster’

7. ‘911’

8. ‘Sour Candy’

9. ‘Telephone’

10. ‘LoveGame’ / ‘John Wayne’

11. ‘Babylon’

12. ‘Free Woman’

13. ‘Born This Way’

14. ‘Shallow’

15. ‘Always Remember Us This Way’

16. ‘The Edge Of Glory’

17. ‘Enigma’

18. ‘Stupid Love’

19. ‘Rain On Me’

20. ‘Hold My Hand’