The 17-year-old crossed for what turned out to be a crucial try in England’s 15-13 win in the first of two matches against Ireland Clubs, in Portsmouth.
The Irish held a 13-5 lead at the break, but tighthead prop Thompson began the comeback when he intercepted a pass from Ireland’s scrum-half and showed impressive speed to score in the corner.
England then scored the winning try with 10 minutes left.
“It was amazing to get the try that started the comeback in the first game, and something I will remember for a long time,” he said.
Thompson, who joined Melton RFC at the age of 10, following his two brothers into the club, was a replacements for the second game as team manager Dave Penberthy gave all of the 23-man squad game time.
This gave former John Ferneley College pupil Harry Clayton his chance, and the Old Dalby front-rower helped England to another narrow win.
“The overall experience was amazing,” Thompson added. “Both games were massively close, both being one-score games, which just added to the jubilation of winning them.”