Olympic medalists Katie Ledecky, Simone Manuel, Melanie Margalis and Chase Kalisz each set championship records in their respective events during the second night of finals at the Toyota U.S. Open at the Georgia Tech McAuley Aquatic Center in Atlanta, Ga.

After winning the 800m free last night, Ledecky cruised to a 4:00.81 in the 400m free in the first final of the night. She cut more than four seconds off her own meet record of 4:04.96, which she set last night at the halfway point of the 800m free. Australia’s Kiah Melverton came in second in a repeat of last night, touching in 4:07.38, while Leah Smith picked up another third place finish with a 4:08.06.

Melanie Margalis, a 2016 Olympian in the 200m IM, used a strong breaststroke leg to surge past the rest of the heat in the final of that event tonight. Margalis touched in 2:08.84 to lower her own meet record of 2:10.71, from this morning’s prelims. Alex Walsh also cleared the meet record with a 2:09.01 for second, while Torri Huske claimed third in 2:11.70.

The men’s 200m IM final featured a great race between Olympian Chase Kalisz and up-and-comer Carson Foster. Foster, who set the meet record in prelims at 1:58.38, had the better of Kalisz for the first half of the race before Kalisz pulled ahead on breast and hung on for the win, 1:57.28 to 1:57.59. Ryan Lochte, the world record-holder, took third in 1:58.89.

American record-holder Simone Manuel topped the women’s 50m free heat in 24.43 en route to lowering her own championship record of 24.65 from prelims. Erika Brown also cleared the meet record with a 24.58 in finals, about three tenths in front of Gretchen Walsh’s 24.83.

Brazil’s Guilherme da Costa added another win to his collection after posting a 3:46.57 in the men’s 400m free final. Da Costa flipped eighth at the first turn and then held the second position until the final turn, where he surged ahead of Kieran Smith (3:47.72) and Ziyang Zhang (3:48.21).

Brazil picked up its second win of the night from Bruno Fratus in the men’s 50m free. Fratus led a trio of swimmers under the 22-second mark as he stopped the clock at 21.72. Zach Apple (21.81) and Michael Chadwick (21.97) rounded out the top three.

Tomorrow’s preliminary races are scheduled to start at 10am EST, with finals kicking off at 7pm EST. Make sure to check out USA Swimming.org for results and a live webcast of all events.