That's beautifully done by Eagles number 10 AJ MacGinty, who pokes a lovely little grubber out of play just five metres from the Samoan line.

Samoa, in white shirts, blue shorts and white socks, can only clear out of play just past their own 22-metre line.

We've seen plenty of Samoa with ball in hand, but here come the States now, working it from left to right - but the move ends when Saracens wing and Eagles captain Chris Wyles sends a pass arrowing straight out of play.

A few moments later, Takudzwa Ngwenya gathers safely under the high ball, only to be absolutely clattered by Samoa's Alesana Tuilagi. Another huge hit.

And Tusi Pisi splits the posts to put Samoa ahead in the Brighton sunshine.

Image source, Getty Images

Back come Samoa, however, and the States are soon penalised for failing to roll away at a ruck. Tusi Pisi will have a shot at goal...

Manu Samoa have settled into the game nicely now, working through the phases inside opposition territory. Fly-half Tusi Pisi, brother of Northampton pair George and Ken, throws a cheeky little offload between his legs to cheers around the ground.

It all breaks down though, and AJ MacGinty clears for the United States.

We agree Daniel, There is no better way to spend a Sunday.

After that early break in play, we'll have a couple of scrums, the second from which the Samoan pack win a penalty as it collapses in a heap on the floor.

Goodness me, welcome to the Rugby World Cup, Rey Lee-Lo. Opposition centre Thretton Palamo goes hurtling into the Cardiff Blues-bound number 12, who bounces to the ground and stays down.

After some treatment, he's withdrawn for Mike Stanley. Lee-Lo's World Cup debut lasts 41 seconds. 

Irish referee George Clancy is the man in the middle, and his whistle prompts United States fly-half AJ MacGinty to kick long. Immediately, his side are on the attack.

With the anthems done, it's time for the Samoans to perform their pre-match war dance, the 'Siva Tau'.

All part of the spectacle - and always enough to send shivers down the spine. This time it's led by the bellowing Newcastle Falcons wing Alesana Tuilagi to complete silence inside the stadium. Brilliant.

Image source, AFP

Don't forget, we're asking you today whether you think Japan's win over South Africa was the biggest shock in sporting history...

The two teams make their way onto the field at a packed Brighton Community Stadium.

The United States are draped in navy blue, Samoa in white and blue.

It looks a stunning day on the south coast.

Image source, Getty Images

To help put Japan's win over South Africa into further context, prior to the World Cup kicking off my colleague Mike Henson investigated what it was like to be one of the smaller nations in the rugby union world, using Samoa as his case study.

In the feature he highlights the pay differential during last year's autumn international series, with Samoa's squad on approximately £500 a week, or around £70 a day, during their northern hemisphere tour - while each of the England players featuring in their match at Twickenham match £15,000.

Click here to read the rather wonderfully-crafted piece in full.

Image source, BBC Sport

In contrast to today's opponents, Samoa have plenty of Rugby World Cup pedigree.

They've twice reached the last eight of the competition, once in their previous guise as Western Samoa, and have picked up at least one win in every World Cup they've played in.

Their most notable victories in the tournament both came against Wales - famously beating them 16-13 in Cardiff in 1991, before repeating the trick eight years later, again in the Welsh capital.

Rob Stevens
BBC Sport at Brighton Community Stadium

Anyone who was here in the ground for Japan's momentous win yesterday will be hoping for more of the same today.

Liz and Richard Wilson were cheering on the Brave Blossoms against South Africa, but they have split loyalties this morning.

She was born in Connecticut so is supporting USA, but he has opted to root for Samoa. Will they still be talking after the match?

Image source, BBC Sport

Image source, BBC Sport

The United States are competing in their seventh Rugby World Cup in England and Wales, but their record isn't one to envy.

They've won only three of their 21 pool matches, with two of those victories coming against Springbok-slayers Japan, and you imagine they'll do well to add too many to that tally in 2015.

The USA do, at least, have one claim to fame - they won the last rugby union Olympic gold medal to be awarded in 1924.

Image source, BBC Sport

Replacements: Phil Thiel, Oli Kilifi, Chris Baumann, Cam Dolan, Danny Barrett, Shalom Suniula, Folau Niua, Brett Thompson.

Image source, BBC Sport

Replacements: Viliamu Afatia, Motu Matu'u, Census Johnston, Faifili Levave, Alafoti Faosiliva, Vavao Afemai, Mike Stanley, Fa'atoina Autagavaia.

Samoa have made nine changes to the side that won the Pacific Nations Cup for their World Cup Pool B opener against the the United States.

Only two backs - Northampton scrum-half Kahn Fotuali'i and Newcastle wing Alesana Tuilagi - survive from the team that beat Fiji.

Samoa beat the Eagles 21-16 when they met at the Pacific Nations Cup in July.

The United States are captained by Saracens' Chris Wyles, with Samu Manoa - who has joined Toulon after four years at Northampton Saints - in the back row.

Rob Stevens
BBC Sport at Brighton Community Stadium

It's a beautiful autumnal morning in Brighton which will please the Samoan players, who complained during the week that it rained here on the south coast every time they trained.

Fans are enjoying the atmosphere outside the stadium, with plenty of USA flags on show, and a few Captain Americas milling around.

Image source, BBC Sport