Twelvetrees only found out he was making his first Tigers appearance 10 minutes before kick off when Dan Hipkiss withdrew through illness.
He said: “It is what every boy dreams of, playing in the Heineken Cup for Leicester Tigers who are such a prestigious side. I loved every minute of it."
He added: “You work hard to get here and I just love playing rugby. It is a great honour to play for Leicester Tigers first team, especially in my first game in the Heineken Cup.”
Twelvetrees alongside Lucas Amorosino and Jeremy Staunton scored their first Tigers tries, to add to Johne Murphy’s second-minute score and secure a try-scoring bonus point. He also took over kicking duties from Staunton, who had received a knock, and added nine points with the boot.
He said: “I practise kicking all week with (kicking coach) Paul Burke and Jeremy Staunton so I was happy to take over.
“I tried to relax and pretend I was on the training field. I knew Paul Burke would be saying to relax, go slowly and hit through it.
“I will get my head down in training this week and work hard. There are a lot of great players in the Tigers squad and to get a chance has been fantastic. Hopefully I will get to do it again.”
Tigers return to action at Welford Road against Northampton Saints on Saturday, October 31 before World Champions South Africa visit on Friday, November 6 to officially open the new 10,000-seat Caterpillar Stand.
Tickets for all Tigers home games are available now on 0844 856 1880 or online at www.leicestertigers.com/tickets