Now the 23-year-old has his sights set on more European glory as Cardiff Blues prepare to take on Heineken Cup holders Leinster at the home of Irish Rugby.
"It is a nice boost for going back there," said Halfpenny.
"It was a fantastic game, especially with the way it ended. For me to be able to contribute with the last kick to win a game for Wales and set us up for what eventually became a Grand Slam was one of the proudest moments of my life.
"If I'm playing in the Leinster game, those memories will come flooding back.
"I'm looking forward to going back there to reflect on those memories and hopefully continue along the same lines with the Blues."
Taking on the reigning Heineken Cup champs and a side that have got the better of the Blues on all but one of the last 10 meetings between the two teams is undoubtedly a difficult challenge but it's one Halfpenny insists he and his team-mates are particularly excited about.
The 2009 Lion believes the confidence brought about by Grand Slam success and the experience of winning in Dublin with Wales can inspire the Blues to fulfil their own potential despite Leinster starting as firm favourites.
"We know what a quality outfit Leinster are. To be going to play them in the Aviva Stadium is going to be huge challenge for us but we're looking forward to that challenge," added Halfpenny.
"We hope to go there with confidence, and we're hoping the confidence of the boys coming back from the Grand Slam will come through with the Blues too. Hopefully that can spread through the whole squad and we can move forward from there.
"That's one thing the international boys will have experienced recently - the Aviva Stadium being packed. It's a great stadium to play in and I've personally got good memories of playing there so far. I'm hoping that will continue."
They say that success breeds success in the sporting world and Halfpenny and co are certainly confident that can be the case as far as Wales and the Blues are concerned.
Picking up the Triple Crown and the RBS 6 Nations Championship trophy has given the converted wing a taste of success on the big stage and now he's looking to follow that feeling by claiming the biggest prize on the club scene with his beloved Blues.
"We've done our job with Wales in the 6 Nations and we've achieved what we set out to do but the season's not finished yet.
"There's still plenty to play for with the Heineken Cup, plus the summer tour to Australia. There's plenty left still to achieve.
"The Heineken is the big one now for us. We believe we can go to Dublin and get a result. We know it's not going to be easy but hopefully we can perform and then go on to pick up some more silverware at the end of the season."