The musician was presenting the Best British Album award to Dua Lipa at the 02 Arena on Tuesday (11 May), but the sound kept dropping out while he was speaking.
This is because Capaldi kept swearing, which left producers on the edge of their seat.
“Hello motherf***ers,” he said, adding: “I’m f***ing sweating. It’s like a swamp down there – sweaty bollocks.
After saying it was “great” to be out of the house following lockdown, Capaldi stated: “it’s been a great year for albums, most of all because I haven’t f***ing released one.”
Capaldi, who was reading from a pre-written card, quipped: ‘And obviously let’s hope that Scotland win at the Euros.”
When the London crowd mock booed, Capaldi exclaimed: “I didn’t f***ing write it!”
Fans watching at home were left entertained, with many calling the chaotic moment “the best part” of the ceremony.
Host Jack Whitehall had also been muted earlier in the evening, leaving many Twitter users wondering what he had said.
It turns out that it was his use of the term “corporate w***ers” that caused bosses to drown him out.
The ceremony marked the first live large-scale indoor event since March last year.
Proceedings got off to a spectacular start with a Line of Duty skit from Whitehall. Meanwhile, there were performances from Coldplay, Arlo Parks, Dua Lipa, and Elton John and Olly Alexander.
Winners included Little Mix, Arlo Parks, Haim and The Weeknd. Find a full list here.