Cory Allen scored three tries for Wales before going off with an injury ©Getty Images

Wales thrashed Uruguay 54-9 in their Rugby World Cup opener but they have more injury concerns after losing Liam Williams, Dan Lydiate and hat-trick hero Cory Allen to the treatment table.

Despite England hosting the tournament, the Welsh capital Cardiff's Millennium Stadium was selected as a venue to give Warren Gatland's side home comforts for their game against the South American minnows, who claimed the last qualifying spot on offer at the World Cup by winning the repechage tournament.

It was predictably comfortable for the Welsh although Uruguay did put the cat among the pigeons somewhat by opening up a 6-0 lead thanks to two Felipe Berchesi penalties.

There was to be no shock to go alongside Japan's slaying of South Africa though as Samson Lee went over for the first Welsh try after 15 minutes, which was converted by Rhys Priestland.

Centre Allen then crossed the whitewash with Priestland converting again, before Berchesi booted over another penalty to leave his side only 14-9 behind.

That was as good as it got for Uruguay as Allen went over for two more tries to complete his treble before the break, both converted by Priestland as the bonus point was secured before half-time.

Samoa beat the United States in Brighton
Samoa beat the United States in Brighton ©Getty Images

Wales led 28-9 at the break and Hallam Amos' try and Priestland's conversion quickly extended that advantage.

There was then worry for the home fans though as Allen limped off with a suspected hamstring injury, while flanker Dan Lydiate and Liam Williams both went off in the game as well.

The Welsh had already suffered injury blows before the tournament when influential pair Rhys Webb and Leigh Halfpenny were ruled out of their squad.

They completed their win as Gareth Davies crossed twice, either side of a Justin Tipuric try, with Priestland converting two of the three.

The result sees Wales go top of Group A, ahead of hosts England in the so-called pool of death which also includes Australia.

Elsewhere, Samoa beat the United States 25-16 in Brighton to go top of Pool B.

Tim Nanai-Williams and Ofisa Treviranus were the Samoan try scorers while Tusi Pisi kicked four penalties and Michael Stanley one.

The US managed tries through Chris Wyles and Chris Baumann, adding to two penalties from AJ MacGinty's boot.

In the last game of the day, defending champions New Zealand played Argentina at Wembley and were given a scare in front of a Rugby World Cup record crowd of 89,019.

The Kiwis eventually came through 26-16 in Pool C but the Pumas led 13-12 at half-time.

Dan Carter’s three penalties had put New Zealand 9-0 up but Guido Petti scored the only try of the half for Argentina, converted by Nicholas Sanchez.

New Zealand were then reduced to 14 men as Richie McCaw was yellow-carded for a trip, before Sanchez kicked a penalty to put his side in front 10-9.

Remarkably the New Zealanders were then reduced to 13 as Conrad Smith was binned for coming in at the side of a ruck, and Sanchez took advantage with another penalty.

Despite being two men light, Carter’s fourth penalty brought New Zealand back to within a point at the interval.

Nerves in the holders' camp increased when Sanchez began the half with another penalty to put his side 16-12 up, but there was to be no shock as Aaron Smith and Sam Cane settled nerves with tries that were converted by Carter.

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