Wales cruised past 2007 World Cup semi-finalists Argentina with a 28-13 victory at the Millennium Stadium in their final warm-up test ahead of September's World Cup. Argentina dominated the opening exchanges but they were hit by a sucker punch by Wales who grabbed two quick-fire tries through Andy Powell and Alun Wyn Jones with James Hook converting both. Hook stretched Wales' lead with a succession of second-half penalties before George North crashed over for yet another try. Argentina grabbed a late consolation through Martin Scelzo which Felipe Contepomi converted but the result was already beyond doubt. Wales were determined to build on the triumph over England last weekend and enter their World Cup opener against world champions South Africa on September, 11, on the back of two victories. Wales coach Warren Gatland was pleased with the manner in which a team that showed nine changes from last Saturday's win over England had coped with a tough Pumas outfit. "We took a bit of time to settle, but we then took our opportunities very well," said the New Zealander, who will name his squad on Monday. "The second try especially was very clinical, and it is about taking those opportunities when they are there. "We believe we are in good shape physically, and we have won five of our last seven games. We have that confidence."  One worry, though, for Wales was they lost veteran fly-half Stephen Jones before kick-off, with a recurrence of his calf injury, with Scott Williams stepping up to the bench but Gatland was optimistic that he would be fit. "Stephen Jones had a scan last night," said Gatland. "He felt the calf a little bit in training, but it is not a huge concern for us." Argentina veteran Contepomi said that it wasn't a bad performance by his side given it was their first test of the year - but they have just one more match before they take on England in their World Cup opener against England on September 10. "That was our first Test for a long time, but I believe we made a step forward," said Contepomi. "In terms of the game plan and structure, we did well, but individual errors in terms of decision-making cost us. "I think we are moving in the right direction, we just need to solve these errors." Contepomi opened the scoring on 29 minutes with a well-taken penalty. Moments later the Argentine fly-half had the chance to extend the visitors lead but was once again off target with the boot. Wales took full advantage moments later when they surged into the lead thanks to Powell's first ever try for his country. Tavis Knoyle broke off the back of a scrappy scrum and linked with second-row Jones who then released Powell to race into the corner. Hook expertly slotted the touchline conversion and they grabbed a second quick-fire try within moments of the restart. Jamie Roberts offloaded out of contact to release George North and the Scarlets flyer beat his opposite number and Contepomi before drawing Martin Rodriguez to put Jones over for a try of his own. Hook was again on target to hand Wales a 14-3 half-time lead. Wales started the second-half with much better effect than the first and they got their reward with a Hook penalty on 44 minutes. He added a second on 53 minutes to extend Wales' lead to 20-3. Argentina were dealt a blow when Juan Fernandez Lobbe was sent to the sin-bin after taking Jones out at the restart. But Contepomi struck-back with a penalty on 62 minutes to reduce the deficit to 20-6. The hosts finished in style with North crashing over for his seventh try in nine matches for Wales. Argentina grabbed a late consolation try with a trademark drive over maul which Contepomi converted but it was not enough and Hook added a final penalty at the death.