TOKYO — At the point in the Tokyo 2020 swim meet when Team USA was starting to think it might need a hero, with the arrival of the fifth of eight days of finals at Tokyo Aquatics Centre, the first thing the Americans had to understand was that Michael Phelps wasn’t suddenly walking through that door — or if he was, it was only to sit in the NBC booth, strap on a headset and tell it like it is for the viewers back home.

The other thing the Americans understood: They had the next-best thing.

Here, onto the pool deck, came Caeleb Dressel, the world’s fastest human in the water, and there, off the blocks, he went. Two furious laps of the pool later, the water around him whipped into a gurgling white froth, Dressel reached the wall first to earn the gold medal in a hotly anticipated 100-meter freestyle final that more than lived up to the hype.

Dressel, 24, finished in 47.02 seconds, an Olympic record and the fifth-fastest all-time, to hold off Australian rival Kyle Chalmers (47.08) and Kliment Kolesnikov of the Russian Olympic Committee (47.44). When it was over, Dressel sat straddling the lane line, arms raised in triumph, weary smile on his face, gazing at the scoreboard for a good 15 or 20 seconds before dropping into the water and accepting the congratulations of his fellow competitors.

“Just trying to take in that moment,” Dressel said of his post-race celebration. “I’m not going to relive [this race] ever again, so I wanted to take that in as much as I can.”

The medal was Dressel’s first individual Olympic gold — to go along with three relay golds, two from Rio de Janeiro 2016 and one from this week — and a strong opening statement in the first of his three individual events here. With golds later this week in the 100 butterfly and 50 free, he would join Mark Spitz (1972) and Michael Phelps (2004 and 2008) as the only male swimmers to earn three or more individual golds at a single Olympics. With relays, he could win as many as six golds, which would put him just behind Phelps (eight in 2008) and Spitz (seven in 1972).

“It is different,” Dressel said of an individual gold vs. a relay gold. “I didn’t want to admit it, but now that I did it, I can. It’s a lot different — you can’t rely on anyone else. It’s just you and the water. There’s no one there to bail you out. It’s tough.”

The United States didn’t need Dressel to be a hero Thursday as much as it needed him to be Dressel.

Even before Dressel had finished his warm-up and made his way to the ready room for his race, Team USA had already pulled off the sort of gold medal upset that can redirect a team’s momentum. Bobby Finke won the inaugural Olympic men’s 800 freestyle, an event in which he ranked ninth in the world entering Tokyo, with a blazing final lap of 26.39, zooming from fourth place at the final turn to a gold medal.

It was the sort of surprise performance — joining the likes of Lydia Jacoby’s gold in the women’s 100 breaststroke, Erica Sullivan’s silver in the women’s 1,500 freestyle and Kieran Smith’s bronze in the men’s 400 free — that has kept the United States on top of the medal counts despite a handful of underperformances elsewhere. The key for the Americans now is staying there.

When it came to the swimming competition, these Olympics were set up to be the Caeleb Dressel Games, with the American sprint star, if all went well, poised for a Phelps-like medal haul, or at the very least Phelps Lite. Dressel had won seven golds at the 2017 World Championships, another six in 2019. He could have targeted seven here, though the coaches’ decision to leave him off the 4x200 free relay reduced that total by one.

In an Olympic moment when the pressure on athletes, and the resulting traumas they can inflict, are being examined like never before, few are bearing a larger burden of expectations in Tokyo than Dressel.

“Pressure is fine,” he said. “It’s when that pressure turns into stress that it becomes a problem … I know my name is thrown out there. I understand it. [But] it’s up to me whether I turn it into stress.”

By the start of Thursday’s finals, the fifth morning of medal events at the Olympic pool, Team USA found itself at a critical point, with Australia close in the medal standings and a string of underperformances — most notably in that 4x200 relay that Dressel sat out — forcing the Americans to recalibrate their goals.

It was always easier for Team USA to lift itself to the top of the medal count when the Americans could pencil in Phelps for six to eight medals — a range he hit in every Olympics between 2004 and 2016 — and Ryan Lochte and Nathan Adrian for another handful. None of them are on the roster in Tokyo.

The United States won 31 medals in 2012 and another 33 in 2016, but even with the addition of three new events for Tokyo 2020 — the mixed medley relay, the women’s 1,500 free and men’s 800 free — getting to the 30-medal threshold again seems unlikely. In both previous Olympics, the Americans took 16 golds, another goal they likely won’t match here.

There appears to be little danger of the United States finishing anywhere but first in the overall medal standings, but the gold medal race between the United States and Australia is full of intrigue. With Zac Stubblety-Cook’s victory in the men’s 200 breast Thursday morning and another expected to come in the women’s 4x200 freestyle relay, the Aussies already have more gold medals at this meet than they did in London and Rio combined (four) — with three days of finals remaining.

But the United States added golds from Finke and Dressel to pull ahead in the gold medal standings, six to five. Counting three additional medals Thursday — Regan Smith’s silver and Hali Flickinger’s bronze in the 200 fly and a silver in the women’s 4x200 free relay — the United States padded its lead in the overall medal standings to 21-12 over the Australians.

The back half of the Olympic meet was stacked in the Americans’ favor all along because of the plethora of relays and sprints, but the final standings could come down largely to how well Dressel performs in his remaining individual races, the 100 butterfly and 50 freestyle, and the relays.

“How our team reacts to a little bit of adversity, [when] things don’t necessarily go our way, and how they come back in the back end of a meet is really, really impressive,” U.S. head men’s coach Dave Durden said Wednesday. “And we’re going to lean into that. We’re going to rely on that, and we’re going to … get after the back end of this meet.”

The 100 free was set up to be the toughest of Dressel’s three individual events, with the field also featuring the defending Olympic champion (Australia’s Chalmers), the Olympic record holder (the Russians’ Kolesnikov) and the world junior record holder (16-year-old phenom David Popovici of Romania.

The best starter in the sport, Dressel, from Lane 5, launched himself to his typical lead off the blocks and turned at the wall in first place. Chalmers, from Lane 7, began making his move just before the midway point of the final lap, at one point appearing to pull even with Dressel. But Dressel surged one last time, held off his rival and scored another gold for Team USA.

From there, the waterworks opened up. Dressel cried on camera as he was reunited virtually with his family back in Green Cove Springs, Fla., via NBC’s satellite hookup. “We’re so proud of you,” family members gushed, as Dressel mostly stood still with his hand covering his mouth, watching the screen and fighting back tears. He cried again on the medal stand as the American national anthem played.

“I cry a lot,” he shrugged.

There are four more events to come for Dressel in Tokyo, four more chances for gold, four more chances to stamp himself as the Phelps of his era. If he cries like this after all of them, he may run out of tears before he runs out of swims.