If this FIFA Women's World Cup has taught fans anything, it's to never underestimate the opponent.
Australia were upset by Italy after two goals from Barbara Bonansea of Juventus, China ran one of the tournament favourites Germany close and Cameroon put up a valiant fight against Canada in a goalless draw.
Attention will now turn to the United States, as they kick off their campaign against Thailand. The last time these two sides faced off was in Columbus, Ohio, when the States scored nine against their less illustrious opponents.
With upsets surely around the corner, Jill Ellis' side will be drilled and ready to go at kick off - here's a few things to keep an eye out for.
The Ability of Thailand's Miranda Nild
At just 22, Miranda Nild is one of the younger players at this summer's tournament. But she's also one of the powerful attacking options that Thailand possess.
Born in California, she recently wrapped up a collegiate career with the University of California Golden Bears, where she made 73 appearances and scored 13 goals.
Internationally, Nild has been part of the Thai program for two years and has scored 12 goals in her 17 appearances. Aside from Nild, only one other player plies their trade in the United States. Although she isn't the most experienced player, her youthful exuberance and speed give her a definite advantage on the field - and she's sure to start every game, if fit and available.
She'll likely be paired up front with 26-year-old Taneekarn Dangda, and will hope to make an impact in the final two group games, should they go down to the States as expected.
Can USWNT Stay Patient if They Don't Score an Early Goal
It's not 2016 anymore.
Thailand's demoralising defeat is a distant memory, and this game will be contested in a World Cup atmosphere - not the confines of an international friendly in Ohio. This tournament brings the best out of teams, and the underdogs are unlikely to roll over.
It's hard to envisage anything other than a United States win, but the margin of defeat should be narrower. As a result, USWNT must stay patient. They must recognise the chances will come. They'll want to start on the front foot, and lay down a marker for the rest of the tournament.
They mustn't get frustrated, though, if the Thai defence stifle them in the early exchanges. Every minute counts, and the States must remain focussed at the task in hand - the opportunities will come, it's a question of when and not if.
Who Will Gain Midfield Supremacy
The key battles in this game are likely to come in midfield.
Lindsay Horan will need to be at her best to combat an experienced Thai midfield, and alongside Rose Lavelle, both players are appearing at their first World Cup. They will need to keep each other calm, and ensure they see plenty of the ball early on.
Julie Ertz is another important figure in midfield, and unlike Horan and Lavelle, she has World Cup experience. Her success in the 2015 tournament could prove invaluable to this United States side, and her big game mentality should enable an element of control from the off.
Thailand, expected to lose heavily, will know the pressure is on the opposition - and will be keen to keep things tight and limit the space USWNT can operate in. If they do, we could have a closer encounter than the billing would suggest.