Bycroft, 24, rescued a point for his side at the death with a diving header that any outfield player would be proud to score.
The Staplewood graduate’s goal also sealed Cardiff City’s promotion back to the Championship, as all of their promotion rivals failed to win.
“It’s wild, to be honest with you. Coming up for the last five minutes, everyone hopes that the goalkeeper will get their head on it,” said Bycroft.
“I thought I should get myself somewhere near the middle of the goal. He put it right on my head. It was incredible!”
Exeter boss Matt Taylor added: “He committed to it, committed to the run and had the belief that the ball might be there and the moment it was.
“He committed to the header – and it was an excellent header as well.”
Bycroft turned professional with Saints in 2018 before departing for Swindon Town in 2024/25 without making a first-team appearance at St Mary’s.