He had joked about 'having a stroke and waking up speaking Welsh' just 10 minutes earlier.
So when stand-up comic Ian Cognito slumped on a chair as if he was having one, the audience thought it was hilarious.
Even after five minutes still motionless, they were still laughing, thinking it was all part of the act.
Except that he really was having a heart attack, and after paramedics were called to the scene at 10.20pm on Thursday, he was pronounced dead at the scene.
He's not the only entertainer who died while performing on stage. Here are some of the others...
The iconic comic and magician passed away at 63 doing what he loved – making people laugh.
On 15 April 1984, the Welsh funnyman was performing on the variety show Live From Her Majesty’s and had just begun his famous ‘magic cloak’ trick with the show’s host Jimmy Tarbuck.
When Cooper suddenly collapsed to his knees half-way through a scene, it looked to viewers as if he was swooning over his female assistant, and the studio audience roared with laughter.
In fact, he was having a heart attack.
In some of live TV’s most horrific ever scenes, the oblivious audience went on clapping and laughing for over a minute while he continued to slowly slump over.
The curtain slowly came down after crew realised something was seriously wrong, but paramedics couldn’t revive him and he was pronounced dead upon arrival at the hospital.
The comedy legend and one half of Morecambe and Wise suffered a heart attack just after stepping offstage after leaving the audience in stitches during a charity gala performance.
Morecambe was performing at a charity event in Tewkesbury on May 27, 1984, to raise money for disabled facilities. His wife Joan, who was in the audience, recalled that he was “on top form”.
After delivering a hilarious performance to a crowd of 400 people, Morecambe left the stage to make way for a band, but during the musical number, he returned to the stage six times, larking about and pretending to play instruments.
When he left the stage for the final time, he collapsed with a heart attack, his third in 16 years, and was pronounced dead soon after.
The guitarist for ‘70s blues-rock bank Stone the Crows, Harvey died onstage in front of 1,000 fans after being electrocuted while performing at Swansea’s Top Rank Ballroom on a rainy day in May 1972.
The Glasgow group, managed by Led Zeppelin's legendary Peter Grant, were just about to begin their set on a stage full of puddles when he touched a microphone which wasn’t earth grounded and was electrocuted.
A roadie tried to unplug the microphone but the 28-year-old was pronounced dead at the scene.
Darrell Abbott, or Dimebag for short, co-founded groove metal band Pantera with his brother Vinne Paul and was considered one of the most influential guitarists in heavy metal history.
Before the band split and bandmates went their separate ways he founded another band, Damageplan, but fans weren’t satisfied and blamed him for Pantera's demise.
During a show in Colombus, Ohio, on December 8, 2004, a furious fan of his former band, former marine Nathan Gale, managed to get close to the stage and shot Abbott in the head three times.
He also killed the band's security guard and an audience member who was trying to revive Abbott. Gale was shot dead by police.
Although a relatively unknown actress in life, Edith Webster made a name for herself by her bizarre on-stage death.
The 60-year-old was playing the role of the grandmother in the play The Drunkard at the Towson Moose Lodge in Baltimore on November 24, 1986.
Her final scene required her to sing “Please Don’t Talk About Me When I’m Gone,” then slump dead on the floor.
Which is what she did - after which the audience gave her resounding applause.
But after a few minutes, it became clear that the actress really had died, after suffering a heart attack precisely during her on-stage death scene.
The next day the play's director Richard Byrd wrote: "There was tremendous applause. Night after night, she died and she died, and last night she died and she really did."
Real name John Marshall Alexander Jr, Johnny was an American rhythm and blues singer who had a string of hit singles in the mid-1950s.
On Christmas Day 1954 his success came to an abrupt end in a break between sets during a show at the City Auditorium in Houston, Texas, when he shot himself dead while playing with a .32-calibre revolver.
His bass player Curtis Tillman said: "Johnny Ace had been drinking and he had this little pistol he was waving around the table and someone said, 'be careful with that thing', and he said 'It's okay! Gun's not loaded, see?' and pointed it at himself with a smile on his face and, 'Bang!'
Following his death, Bob Dylan, Elvis Presley and Paul Simon performed tribute covers of his songs.
Indonesian pop star Irma was famous for using snakes as props during her act.
But while performing in Karawang, West Java, in April 2016, she accidentally stepped on the tail of a king cobra, which then bit her.
But the singer then refused an antidote from the snake handler and carried on performing for another 45 minutes before she started vomiting on stage and collapsed.
She suffered a seizure and was rushed to hospital where she then died.
Irma reportedly believed the king cobra, which can release enough venom in one bite to kill 20 people, had been defanged.