Head coach Warren Gatland has handed the Cardiff Blues pair a dream international debut against the world champions at the Millennium Stadium.
Wing Halfpenny, still just 19 years old, caps a stunning start to his first season at senior level and becomes the 60th teenager to represent Wales.
He said: “It’s a dream come true to pull on the red jersey. My parent burst into tears when I told them I was in the team. Hearing my name being read out was the best feeling ever.
“It’s amazing because I grew up watching these players with two Grand Slams. Now I’m playing alongside them. I can’t believe how quickly things have progressed.
“I’ve been playing with confidence and to get my first start against the world champions is unbelievable. Now I will do my best to give a great performance.”
No8 Powell replaces the injured Jonathan Thomas to pack down alongside captain Ryan Jones and British Lion Martyn Williams in an impressive back-row trio.
It completes a long-awaited comeback for the former Wales Under-21s star who began his career with Newport eight years ago but has been hampered by two major shoulder operations in recent years since joining the Blues.
Powell said: “It’s great news. There were times when I considered giving up when I had two major shoulder operations but I stuck with it and I’ve finally put my injuries behind me.
“I’ve been given the chance to play regularly at the Blues and I think I’ve taken my chance and played well.
“I hope to make the most of my call up. It boosts your confidence when Warren says positive things about you. I can’t wait to get on the field.”
