What a difference a day, or a performance, can make in tournament football.

Improved depth in the world of women's soccer has given the 2024 Paris Olympics a stacked 12-team field with three challenging groups.

Because of that, getting off to a hot start can give a nation room for error moving into the second and third days of the competition.

And for one program near and dear to the hearts of many in the American audience, it has provided a new spring of hope for the one-time Olympic final fixture known as the United States women's national team.

United States

The resonance of the USWNT's 3-0 win over Zambia may not last past the next match for Emma Hayes' crew, but right now it's sounding very bright and melodic notes.

The Americans were always going to find scoring chances against attack-heavy and defending-weak Zambia, but Hayes' team was about to be tested by the best forwards it's faced since taking over the USWNT program.

And with Germany next, the clean sheet delivered by and for goalkeeper Alyssa Naeher could also be considered the best part of the three-goal win even if there were doubts from many about Hayes leaving longtime star forward Alex Morgan off the roster.

Yet the biggest reason the USWNT are big winners of the day is the early red card shown to Zambia's Pauline Zulu with the favorites already up 3-0. Five bench players were able to ring up 25-plus minutes of Olympic experience and only one involved an injury.

The game isn't without worry given Sophia Smith's late first-half injury, but Thursday was a good day for a program desperate to get back on the podium. Vibes will be high and there's now margin for error against Germany.

Spain

The top team in the FIFA rankings to not claim a win on Thursday was world No. 7 Japan. It's no shame that they fell given who beat them: reigning World Cup winners Spain.

But it's also a feather in the cap of Spain, which has, well, some really outstanding headwear plumage in the first place.

Spain trailed 1-0 on Aubo Fujino's powerful free kick and that was an early reason for concern. But the Spanish kept nearly 70% possession and limited Japan to four total shot attempts in dominating the rest of the way. The goals coming from World Cup stars Aitana Bonmati and Mariona Caldentey were icing on the cake.

A 2-1 win was neither audacious nor unexpected, but it was really, really good.

Germany

The second-most impressive win of the day goes to the Germans, who didn't just beat world No. 12 Australia.

They towered over the Matildas.

Possession may have been shared but the Germans showcased strength and power in taking 15 shots to Australia's eight and physically overpowering their opponents without too many purposeful fouls.

Three different goal scorers dotted the sheet as well, with Wolfsburg duo Marina Hegering and Jule Brand joined by Bayern Munich star Lea Schuller in scoring the goals.

And if the U.S. was happy to have three points in the bag before meeting Germany, this win guarantees an uncertain Australia will await the USWNT on the final day.