Caerau were leading 3-2 against Pontyclun, but the thrilling contest had to be stopped due to a classic case of floodlight failure.
The 49-year-old former England international had agreed to take part following an invitation from the club's secretary Dai Hooper, who once met him at a function.
The Sky Sports pundit went into the game fully committed, and played 65 minutes of the match.
After the game Merson said he would happily play for the Welsh Division Three side again if his time allowed him to.
"I didn't play very well but the team were winning which is the main thing," he told Sky Sports.
"It's a great crowd – and so far so good, except the floodlights have gone off.
"It's not a one-off. I said I'll sign and I'll play midweek. I love playing and if I can keep on playing then I will."
Paul Merson makes an appearance for Caerau against Pontyclun. October 18, 2017
Main image photo by Lewis Mitchell
