Coach Paul John admitted that despite the success it was a hard day. He said: "We knew that it would be a tough pool. We had a dog fight with Scotland. They're a very good side. People don't realise how good they are.
"Then Canada, who beat us the last time we played them. They've just won the Pan Am games. Thankfully we managed to get through those first two games and that guaranteed us a place in the Cup quarters.
"We were able to relax and show what we could do against Australia. I thought the boys were outstanding in that last tie."
Few would disagree about the Welsh performance against Australia. Down 12-14 at the break with tries from Owen B Williams and Ifan Evans and a conversion from Evans, Wales stepped up their effort in the second half to overwhelm the Wallabies.
Richard Smith put Wales on course in the second with a fine try converted by Rhys Patchel and then added a second again converted by Patchel. Wales were playing superb sevens rugby and crowned a great display with a try from teenager Tom Habberfield after good approach work by fellow rookie Harry Robinson, Patchel adding the conversion for a 33-14 win.
Earlier in the opening tie of the tournament Wales came from behind to beat Scotland 14-7 with a try from Tom Prydie , converted by Alex Walker, and then a touchdown and conversion from Will Price
Wales then faced Canada, the fourth seeds in Pool D. The expectation was that Wales would have a comfortable win over the Canadians who are no longer permanent members of the World Series circuit.
But there was an initial shock for Wales as Canada played clever sevens rugby to lead 12-5 at half time with two tries from Sean Duke and one conversion from Nathan Hirayama to a try from Ifan Evans.
Wales, however, began to dominate play in the second half from accurate work in the contact area, reflected by a try from Rhys Patchel. Wales were still trailing by two points but a fine score from replacement Harry Robinson provided the winning points for a narrow 15-12 victory.
Wales Squad Tom Prydie, Will Price, Rhys Patchel, Alex Walker, Tom Habberfield, Harry Robinson, Owen B Williams, Ifan Evans, Rhys Shellard, Richie Pugh, Richard Smith, Owen P Williams