World Cup favourite the USA has thrashed Thailand 13-0 to lay a marker down to the rest of the competition in its opening match in Riems, north-east France.

Key points: The USA recorded the biggest ever Women's World Cup victory

The USA recorded the biggest ever Women's World Cup victory Alex Morgan scored five goals for the world number one side in the 13-0 rout

Alex Morgan scored five goals for the world number one side in the 13-0 rout Some pundits suggested the US should have 'pulled back', while others say the players are not to blame

But some pundits have criticised the American players for both their ruthlessness in dishing out such a defeat, and excessive celebrations late in the game as the goals piled up.

Former Canada player and broadcaster on Canadian network TSN Kaylyn Kyle said she was "disgusted" at the way the US players conducted themselves, while commentator Rob Stone suggested they should have "pulled back" once the match was in the bag.

Another former Canadian international, Clare Rustad, also unleashed on the US team on the TSN coverage.

"I just think they could have won with some humility and grace, and they just couldn't manage to do that," she said.

"Celebrating goals later in the game like this is just completely unnecessary. What is this?"

Leading 3-0 at half-time, the world number one USA exploded after the break, scoring four goals in 10 minutes, before adding another six in the final quarter of an hour.

The score line is the biggest ever in a Women's World Cup, eclipsing Germany's 11-0 thumping of Argentina in 2007.

The USA's previous biggest victory at the World Cup came in 1991, when it beat Chinese Taipei 7-0.

Star striker Alex Morgan scored five goals against the number 34-ranked Thailand side, with Rose Lavelle and Samantha Mewis both netting a brace.

Lindsey Horan, Megan Rapinoe, Mallory Pugh and Carli Lloyd also found the back of the net to give the reigning champions the best possible start to the tournament.

Alex Morgan capitalised on the chances the USA created. ( AP: Alessandra Tarantino )

Result felt 'gross'

US football writer Kim McCauley said the result was an uncomfortable one, but the US players were not to blame.

Loading

Others pointed out there is rarely talk of a men's team over-cooking a result, even though there have been plenty of one-sided matches in male football, including Germany's 7-1 win over Brazil at the 2014 World Cup.

Loading

Loading

"The bottom line is that this game was not fair or ideal for either team," former US international Yael Averbuch West wrote on Twitter.

"The USWNT shouldn't even have to consider not playing and celebrating 100 per cent. Thailand shouldn't be competing from such a disadvantaged position [support and funding].

"Both did their best given the situation."

Morgan said after the match: "We just came into this game [and] really wanted to showcase ourselves and what we've been preparing for and what we've been working on, I think we did that.

"Every goal matters in this tournament and so that's what we were working on this game.

"We got a lot of attacks and I think that we were really clinical in the number of attacks that we did get."

The USA had 39 shots to Thailand's two, winning 10 corners to zero off the back of a dominant 75 per cent possession.

The result continues the United States' exceptional pre-World Cup form, in which it has won seven matches in a row, scoring 36 goals.

The US has not conceded a goal since it beat the Matildas 5-3 in Colorado in April, a run of five consecutive matches.

Thailand, playing in just its second World Cup, had its players leave the field in tears after the heavy defeat.

Morgan, who consoled her upset opponents after the match, was modest after netting her five goals.

"It's incredible, I don't know, I'm speechless," Morgan said.

"The ball just bounced my way tonight … I'm just looking forward to getting onto the next game now."

The USA takes on Chile in its next match of the tournament on Sunday night.