They scored 18. Conceded zero. Wowed millions. Disappointed very few. The U.S. women are moving on to the knockout rounds of the 2019 World Cup after 270 near-flawless minutes of soccer.

The Americans completed a perfect group stage on Thursday with a 2-0 victory over Sweden. Their superiority was even more comprehensive than the scoreline suggests.

And while the USWNT’s goals were somewhat fluky, their dominance was anything but.

Lindsey Horan put the U.S. ahead inside three minutes, stabbing home a Megan Rapinoe corner that trickled through the goalmouth:

Forty more minutes of, primarily, U.S. control and chance-creation didn’t yield a second goal. But a controversial non-call and a deflection did after halftime. And the USWNT cruised from there.

It’ll move on to play Spain in the Round of 16 on Monday at Noon ET. If all goes well there – back in Reims, where the U.S. smashed Thailand 13-0 – the tournament favorite will move on to likely meet its top challenger, France, in the quarterfinals.

But this USWNT fears nobody. Nor should it.

Thursday’s test was billed as the biggest yet. The Americans passed it with ease, even without arguably their most important player. Julie Ertz was sidelined by a minor hip contusion. The midfield was still dominant without its enforcer.

There were only two blemishes on Thursday’s performance. One was the knock star striker Alex Morgan took in the first half. She was removed at halftime, replaced by Carli Lloyd. But it’s unlikely there is any serious injury concern.

The other was final-third imprecision. Morgan wasn’t great while she was on the field. Rapinoe was off her game. But the second goal arrived five minutes into the second half. It locked the U.S. in atop Group F. And none of the nitpicked shortcomings mattered.

U.S. goes up 2-0 thanks to idiotic rule

The result remained in doubt until the 50th minute, when Tobin Heath’s deflected cross looped over Swedish goalkeeper Hedvig Lindahl and into the net. It was eventually – correctly – ruled an own goal. The U.S. won’t care.

But that wasn’t the subject of controversy. Lloyd’s impact on the buildup was.

Lloyd was clearly in an offside position when Megan Rapinoe sent in a cross from the left. She never touched the ball, but her presence required a Swedish defender to attempt to clear the ball. That attempt failed, the ball came to Heath, and seconds later it was in the back of the net.

Lloyd – who, again, was in an offside position – clearly influenced the play. VAR recognized this, and the referee went to her pitchside monitor to check replay.

But by rule, the defender’s “deliberate” attempt to play the ball precluded any offside decision. No matter, according to soccer’s lawmakers, that the only reason she had to “deliberately” play the ball was that if she didn’t, Lloyd was waiting to pounce.

The U.S. benefitted from the rule. That doesn’t make it any less nonsensical.

But any grumblings about rules shouldn’t take away from the USWNT’s excellence, either. Especially in the middle of the park.

Is Sam Mewis too good to bench?

For the better part of a year, head coach Jill Ellis’ first-choice midfield has been clear and relatively uncontroversial. Julie Ertz is the destroyer. Lindsey Horan is the all-around force. Rose Lavelle is the playmaker.

And Sam Mewis, when those three were healthy, has been on the bench.

But Horan was recovering from an injury last month. Becky Sauerbrunn’s minor knock last week pushed Ertz to center back against Thailand. Ertz’s slight injury kept her out on Thursday against Sweden.

All paved the way for Mewis, who scored twice against South Africa and again vs. New Zealand in warmup friendlies. She bagged two in the demolition of Thailand. The rumblings – How could Ellis possibly bench her? – began.

Thursday’s performance, though, was Mewis’ best yet. She was clean and decisive on the ball. She pinged cross-field passes and slid in Morgan with a precise through-ball. She unleashed one rocket of a shot that troubled Lindahl. She presented Lloyd with a glorious chance to extend her record-breaking goal streak late on.

Surely such an influential player has to start ... right?

Superficially, the answer is yes. On the other hand, Lavelle was just as lively on Thursday for 60 minutes. Horan is the reigning NWSL MVP, and arguably the USWNT’s most talented player. Ertz has no equal, is the one semi-true defensive mid, and is probably undroppable if fit.

So what will Ellis do?

We’ll find out on Monday. One option would be to slide Ertz back into the center of defense, replacing either Sauerbrunn or Dahlkemper. Ertz played there at the 2015 World Cup and 2016 Olympics before transitioning to midfield.

Otherwise, it’s likely a decision between Lavelle, Horan and Mewis. And it’s a problematic one.

But in reality, Ellis can’t go wrong. The depth at her disposal is preposterous. As is so much else about this team. Preposterous in the best of ways. It’s humming through the World Cup, and showing no signs of slowing down any time soon.

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Henry Bushnell is a features writer for Yahoo Sports. Have a tip? Question? Comment? Email him at henrydbushnell@gmail.com, or follow him on Twitter @HenryBushnell, and on Facebook.

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