The gag has come off and Winnipeg illusionist Darcy Oake is celebrating a royal milestone.

"I'm finally allowed to talk about it! I had the absolute honour and privilege of being of one of five acts to perform for the Queen and the entire Royal Family at Windsor Castle for the Queen's 90th birthday!" Oake posted on Facebook on Monday morning.

The performance took place April 21 but Oake wasn't allowed to share the news until now — though he was bursting to announce it much earlier.

In his Facebook post Monday, Oake called performing in front of the Queen "the most surreal and amazing experience of my career/life!

"Looking back it's literally amazing where hard work, tenacity and persistence can take you. If you would have told a 15-year-old me that one day I would be entertaining the Royal Family inside the Queen's castle, I obviously wouldn't have believed it! The Royal Family was amazingly nice and this is a story that someday I will be telling my grandchildren!"

Oake has been plying his trade for years on smaller stages but shot to stardom two years ago when he wowed audiences as a contestant on the TV show Britain's Got Talent. The judges were exuberant, with the notoriously tough Simon Cowell saying "We are witnessing the birth of a star."

Despite the praise, Oake didn't win the competition — he placed fifth. But the appearance and media attention did help him land an agent, which has led to numerous high-profile performances and tours.