The young midfielder stepped out for his first Spurs start in the Cup tie at Brunton Park on Wednesday night - four years after making his debut as a substitute in the UEFA Cup.
"I was buzzing to be out there," Mason told Spurs' website. "It's not easy to go to places like Carlisle but the lads did well and it's great to get through to the next round.
"They made it difficult but once we got the second goal, the game opened up a little and we got the ball down and started playing.
"I was a bit disappointed not to score - the goalkeeper pulled off two world-class saves.
"I thought the first header was in and I was off celebrating! But as I said, it was just great to be out there."