Priestland has been on Wales' radar for some time but has watched in frustration at the Scarlets as several of his younger teammates got international recognition before him.
But he admits his debut was worth the wait particularly after not making it off the bench against England.
He said: "Last week I was a bit disappointed being the only replacement not to get on. I am just delighted and hopefully I can get a few more.
"It is something I didn't think was going to happen a couple of years ago, but there are a lot of people who have put a lot of hard work and time in, which I am very grateful for, the coaches at the Scarlets.
"I enjoyed the anthem when the band stopped playing, that was special and coming to the game with all the fans and the pipers. The atmosphere was fantastic last weekend in Cardiff and equally special today.
"Hopefully I can be involved in the remaining three matches in the campaign and hopefully play a bigger role.
"I have really enjoyed my three weeks in camp, I am enjoying every minute."