Ross Moriarty feared his Rugby World Cup might be over just 90 seconds after he came on in Wales' quarter-final win over France.
Moriarty was called upon earlier than expected at Oita Stadium on Sunday, replacing the injured Josh Navidi in the first half.
The back-row was soon back on the sideline after being shown a yellow card for catching Gael Fickou with a high tackle.
Moriarty returned to score a decisive late try, having feared referee Jaco Peyper may have ended his tournament and potentially brought Wales' campaign to an end.
"I was just thinking, 'please, please don't be a red'," said Moriarty.
"That was definitely a big moment. I had been on for only 90 seconds and I was thinking to myself, 'if he gives me a red card, this is the end of me'.
"I knew how bad that would be for the team. I've been in that situation before and it's not a nice feeling. I never go into a game intending to do anything that would get me a card or put the team at any risk of not winning.
"It was a mistimed tackle. I closed my eyes and thought he was going to run round me, but he stopped and ducked under me."
He added: "It was nice for me to know I didn't cause any damage. I talked to him [Fickou] after the game and he was absolutely fine. We had a good laugh.
"I knew when I came back on I had to be very, very squeaky clean and make sure I didn't do any more damage to the team and myself.
"But it does stick in your mind. I was thinking, 'Please, no one come near me'. Sometimes people slip up in tackles, players duck and dive. It's a contact sport - it's inevitable sometimes. Fortunately, there were no other incidents in the game."
