Coventry's Ashley Tait scored with 113 seconds of overtime left to clinch the Grand Slam with a 2-1 Elite League play-off final win over Nottingham.
After Coventry had dominated the first period, Neal Martin put them ahead 38 seconds after the restart with a fierce shot which flew in off the bar.
But Neil Boynton equalised 40 seconds later from just inside the blue line.
Both sides had chances to win it before Blaze captain Tait finished with style from the right wing to secure victory.
Coventry join Sheffield and Ayr in completing the clean sweep in the past 10 years, having already won the League title and Challenge Cup this season.
Coach Paul Thompson could not hide his joy following Coventry Blaze's achievements.
"I said to the guys in the round robin stage that Nottingham were our toughest opponents and they they proved that," said the Coventry coach.
"When you are on a roll things do bounce for you but you still need the quality to take those opportunities.
"They can be proud of what they have done on Sunday."
Nottingham Panthers coach Paul Adey looked on the bright side despite seeing his team defeat.
"I'm very proud of the team and to get this far was a real feat," he said.
"Great teams find a way to win. We made one mistake and paid for it. It was a great game.
"As a player and a coach you are just thankful to be a part of a game like that. We've nothing to be disappointed about after that effort."