"We've got to congratulate ourselves for winning against a good team and getting to this stage," said Wilkinson.
"But there's work to do - this tournament is only going to get harder. I've seen this game for 16 years and I know the guys here are as good as any team I have played with.
"The end of the game was disappointing. It doesn't matter if you're a little bit ahead or in a tight game.
"We let a few tackles go, we let them come through the line and, ultimately, they scored a few good tries. It's not the way we want to finish any game.
"Cardiff started very well and we got caught a little bit cold with the try at the start. We picked up the pace, stuck together as a team and we built momentum and got a bit of a grip on it."