Williams is one of four players making their debuts
Wales new-boy Owen Williams is relishing running out at the Hanazono Stadium to win his first cap against Japan tomorrow.
The Cardiff Blues centre is one of four players making their senior international debuts alongside Dafydd Howells, James King and Emyr Phillips.
And the Aberdare product is determined to savour every moment of the landmark occasion.
"We were in a team meeting and to see my name on the screen was amazing," said Williams.
"It's very exciting and I'm really looking for to winning my first cap. I'm sure I'm going to be nervous, but I want to enjoy it and remember every moment of it.
"I couldn't ring home straight away because it was the middle of the night and we were going straight to training. So I had to wait to ring, but now my parents are coming out to watch the game."
Williams enjoyed a breakthrough season for the Blues, widely impressing with 20 appearances in the midfield and on the wing for the region.
And the 21-year-old is determined to take centre stage as Wales bid to continue the form of their triumphant RBS 6 Nations campaign.
"This has been a breakthrough year for me," said Williams.
"I've had a lot of game time with the Blues and I've been happy with the year I've had.
"I played a lot on the wing because of injuries, but this (No. 13) is my best position.
"It has been great to get some games under the belt and I'm already looking forward to next season. The Blues are going to be a lot stronger because a lot of youngsters like myself who had just stepped in this season have now had a lot more experience so should be better for it.
"This (first cap) is the perfect way to finish off a good year.
"It's a chance to put your hand up and put your name in their heads for when they pick the next few squads."
While Williams is taking his first steps into the Test arena in Japan, his regional teammate, Racing Metro-bound Jamie Roberts is starring for the Lions.
And Williams admits he has learned a huge amount from the British & Irish Lions mane man.
"It helps a lot with the experience he has got," added Williams.
"He helps you along, talking a lot through the game and it just lifts you because you're playing alongside him. He gives you confidence."
Wales and Ospreys back row James King, who came through the North Wales age grade system, nominated North Wales Regional Community Rugby Manager Marc Roberts, in the WRU's 'Diolch' initiative where squad players thanked those who played a part in their rise to the top.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series