Iestyn Harris saw his schoolboy dream turn into a nightmare as Argentina crashed his debut party, triumphing 21-16.

The 25-year-old quickly discovered the harsh realities of international life following his £1.5million code-switch as two errors were ruthlessly punished by the South Americans.

Harris, who had pictures of Welsh outside-half legends Barry John and Jonathan Davies on his bedroom wall as a teenager, did finish with an 11-point haul.

But the former Leeds rugby league star, who decided at 17 he would one day switch from league to union, was outshone by opposite number Felipe Contepomi who scored 25 points as Argentina claimed the one Six Nations scalp missing from their collection with a well-deserved victory.

Harris had been hailed as Wales' latest genius in the hallowed number 10 shirt following his 31-point contribution for Cardiff in their Heineken Cup clash against Glasgow last month.

But his own belief that it will take him over a year to adapt to the union game following his arrival from Leeds Rhinos was proved in the much quicker environment of Test rugby.

The ex-Great Britain and Wales international was not helped by another insipid and lacklustre display by the Welsh forwards - the returning No 8 Scott Quinnell excepted - as they produced a repeat of the horror show against Ireland.

Wales struggled to win clean line-out ball, were outgunned in the scrums, were generally outmanoeuvred by the beefy and more street-wise Pumas pack and constantly lost promising positions with turn-overs.

Harris, silent but clearly moved by the occasion during the singing of the National Anthem as he was almost enveloped in the arms of giant second row Craig Quinnell, was never given time to display the ball-running talents he showed in league.

It was nearly four minutes before he got his first touch of the ball, but his first meaningful action nearly resulted in an Argentinian try and he dallied too long over a clearance kick near his own line.

The ball was easily charged down, but somehow Wales managed to clear the danger though Harris had not learnt his lesson as he showed in the 34th minute.

Harris again wanted too much time with his clearance kick and Bristol's Contepomi did not allow him it as he charged down the kick about 25 metres out.

Contepomi chased after the loose ball and showed skills with his feet that countryman Diego Maradona would have been proud of as he controlled the ball before grabbing the try.

The 24-year-old, who had earlier kicked a penalty, added the conversion and within minutes had slotted home another penalty to suddenly give his side a 13-point lead.

Wales - and Harris - desperately needed a moment of inspiration and they got it as Scott Quinnell, who missed the Six Nations debacle against Ireland, produced a trademark charge down the middle.

Harris, who had earlier found fellow rugby league convert Anthony Sullivan with a long pass, was in support and again found his Cardiff clubmate on the left.

Sullivan, son of the late league legend Clive who was also making his union debut for Wales, burst through and found flanker Colin Charvis in close attendance and he drove to the line.

Harris was twice more involved in the move as Wales finally took advantage of a huge overlap for prop Darren Morris to plunge over for his first try for his country right on half-time.

The 39,000 crowd in the 74,500-stadium then let out the biggest cheer of the afternoon as Harris, watched by his parents, scored his first points for his country with the conversion.

But there was still time for Contepomi to punish Wales for conceding another penalty with a strike that gave his side a 16-7 advantage.

Wales badly needed an early second-half score and they should have had it through Sullivan, but full-back Kevin Morgan, who had made a devastating break from his own-22, threw out a wild pass which the left-wing had no chance of catching.

Harris did pull three points back soon after with a successful penalty, but just when Wales must have hoped for a comeback he produced another error that was immediately punished.

Instead of attempting to find touch, Harris meekly chipped ahead from his own 22 and the loose ball was soon gathered up and passed to left wing Gonzalo Camardon who raced in virtually unopposed to score in the corner.

Harris added two more penalties but Contepomi responded with three of his own to seal a convincing first victory for his side against Wales in a capped game.

Salt was rubbed into the wounds of Harris as Contepomi was rightly named Man of the Match when the nation had come hoping to see the birth of a player to follow in the footsteps of John, Phil Bennett and Davies.

The crowd reacted to another Welsh defeat with boos as the pressure was piled on Kiwi coach Graham Henry, who has claimed the match was the start of his rebuilding for the 2003 World Cup.

Harris should be a major part of the restructuring and he will hope for a more productive afternoon against Tonga next weekend before world champions Australia come calling.