BUDAPEST, Hungary – While the spotlight is on Katie Ledecky any time she swims, Caeleb Dressel was able to bask in some of that glow Sunday at the 17^th FINA World Championships.

Dressel, the 20-year-old Olympic gold medalist competing in his first long course World Championships, set two American records and won a gold medal in the 400m free relay on day 1 of the competition.

His American records were two of five set Sunday at the Duna Arena, and his gold medal just one of three for the United States.

His first American record came in the semifinals of the men’s 50m butterfly, where his time of 22.76 qualified first for tomorrow night’s finals by one-hundredth of a second over Adrii Govorov of Ukraine.

His second came as the leadoff for the American men’s 400m free relay. His time of 47.26 paved the way for teammates Townley Haas, Blake Pieroni and Nathan Adrian to hold off Brazil by 28-hundredths of a second for gold in 3:10.06.

“It feels good,” Dressel said. “That’s seven-tenths faster than I was at (World Championship) Trials, so I’m excited. Any time you can find new ways to go faster in an event and get experience along the way, it’s good.”

It marked the first time the U.S. won gold in that event at a World Championships since 2009.

“A lot of these meets, you’ve got to be on top of your game both mentally and physically – all of Team USA,” Dressel said. “That’s why we go to camp – to get everyone in the correct mindset to do our best for the U.S.

“It’s a collective effort. It’s teamwork here. I’m only 25 percent of that relay. I tried to do my 25 percent the best I could. I just wanted to do my part, and that’s it."

As for Ledecky, she was her usual, dominant self.

First, she won gold in the women’s 400m freestyle, shattering the meet record she set in this morning’s prelims by 72-hundredth of a second in 3:58.34. It was the second-fastest performance of all time in the 400, behind the world record of 3:56.46 she set last year at the Olympic Games in Rio. It was also her third straight World Championships title in the 400. Teammate Leah Smith finished about three seconds behind in 4:01.54.

Later, Ledecky was back in the pool for the women’s 400m free relay, where she and her teammates Mallory Comerford, Kelsi Worrell and Simone Manuel edged Australia for gold in an American record time of 3:31.72.  Comerford’s lead-off time of 52.59 was also an American record.

It was the first time the American women won gold in this event since 2013.

“I think as a team we set a goal from the beginning of training camp that we wanted to make a statement with this relay,” Comerford said. “It’s been a while since we’ve been on top. I think we really achieved that, and made a statement with that, and I think we still have room for improvement, which is exciting for the future.”

For Ledecky, her gold in the 400m free relay marked her 11^th career World Championships gold medal, a tally that now ties her with Olympic teammate Missy Franklin for most career World Championship golds. Ledecky will swim four more events this week, including the 200, 800 and 1500m free, and the 800m free relay.

“It’s a great honor, just to be on a relay and do it that way,” Ledecky said. “It’s a great honor to be on a relay with those girls. I’m just taking it one swim at a time and trying to put together some good races.”

The other swimmer turning in an American record Sunday was Kevin Cordes in the semifinals of the men’s 100m breaststroke. His time of 58.64 qualified him second for tomorrow night’s finals behind world record-holder Adam Peaty of Great Britain. Peaty’s time of 57.75 Sunday was a World Championships meet record.

Other American swimmers competing in semifinals Sunday were Worrell in the women’s 100m butterfly (3^rd, 56.74); Sarah Gibson in the women’s 100m butterfly (15^th, 58.48); Tim Phillips in the men’s 50m butterfly (7^th, 23.25); Cody Miller in the men’s 100m breaststroke (3^rd, 59.08); Melanie Margalis in the women’s 200m IM (2^nd, 2:08.70); and Madisyn Cox in the women’s 200m IM (6^th, 2:09.97). The top 8 swimmers in each event will compete in tomorrow night’s finals.

Also swimming in tonight’s finals was Zane Grothe, who finished seventh in the men’s 400m free in 3:45.86. Grothe is competing in his first long course World Championships.