Hubert Kos crushes U.S. Open Record, Leon Marchand cracks French Record in 200 back

2025 SWIMMING WORLD CUP – CARMEL

• October 10-12, 2025
• Carmel, Indiana
• SCM (25 meters)
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  • Prelims: Day 1 | Day 2
  • Finals: Day 1

Among the flurry of U.S. Open records that fell on Night 1 of the World Cup in Carmel was the men’s 200 backstroke, which saw a pair of training partners push themselves to absolutely shatter Shaine Casas‘ previous mark of 1:48.40.

The Texas duo of Hubert Kos and Leon Marchand both dipped under Casas’ old record, with the Hungarian taking the win in the event in which he is the reigning Olympic, world short course and world long course champion.

Kos dropped his second-fastest swim ever to go 1:46.84, pulling away from his teammate on the final 50. Marchand took second behind him in 1:47.68, a huge new personal best and a French record by nearly a second.

Kos holds a best time of 1:45.65 from the Short Course World Championships last December, but this appears to be a first elite-level swim for Marchand in the event. He took on a pair of off-events on Day 1 in Carmel, also taking silver in the 400 free.

Marchand was out quick, leading the field with a 25.03 first 50 and flipping half a second ahead of Kos at halfway, 52.60 to 53.10. The gap narrowed to just eight-hundredths of a second at the 150m mark, before Kos threw the hammer down with a 26.46 final 50. That was the fastest in the field by nearly a second and one of only two under 28 seconds, the other being Marchand.

Split Comparison

Kos fid his damage on the final 50 compared to the U.S. Open Record as well, taking more than a second and a half out of Casas over those two lengths.

Rounding out the podium last night was Casas, also a member of the Texas IM/backstroke training group, and the third member of the 200 IM podium from this summer. He was 1:49.81 for a comfortable 3rd, the only other swimmer to break 1:50, and was more than two seconds ahead of Joshua Edwards-Smith in 4th. Casas later went on to set a new U.S. Open record in the 100 IM to close out the session.

The 200 backstroke is the only 200 event in which Marchand has not held either the World Record (200 IM), Olympic Record (200 fly, 200 breast, 200 IM) or NCAA Record (200 free, 200 breast, 200 IM). However, his phenomenal underwaters allowed him to claim a French record in the short course event last night, breaking Mewen Tomac‘s 2023 mark by nearly a second.

Surprisingly, despite Marchand rocketing out ahead of his teammate Kos in last night’s race, he flipped at the halfway mark seven-hundredths off a second slower than Tomac did when setting the record at the European Short Course Championships in 2023.

Tomac, who had won the 50 and 100 backstroke already at that meet, hit the 100m mark in 52.53, but faded hard on the last 50. Marchand closed a full second faster than the E.N.Caen swimmer, 27.38 to 28.39.

Split Comparison

Marchand now checks in as the 10th-fastest man in history. Kos, who remains as the 2nd-fastest ever, had the 7th-fastest swim in history last night.

Top 10 Men’s SCM 200 Backstroke Performers All-Time

1. Mitch Larkin (AUS) – 1:45.63, 2015
2. Hubert Kos (HUN) – 1:45.65, 2024
3. Arkady Vyatchanin (RUS) – 1:46.11, 2009
4. Evgeny Rylov (RUS) – 1:46.37, 2020
5. Ryan Lochte (USA) – 1:46.68, 2010
6. George Du Rand (RSA) – 1:47.08, 2009
7. Ryan Murphy (USA) – 1:47.34, 2018
8. Radoslaw Kawecki (POL) – 1:47.38, 2014
9. Markus Rogan (AUT) – 1:47.64, 2009
10. Leon Marchand (FRA) – 1:47.68, 2025

Men’s 200 Backstroke – Final

• World Record: 1:45.63 – Mitch Larkin, AUS (2015)
• World Junior Record: 1:48.02 – Kliment Kolesnikov, RUS (2017)
• World Cup Record: 1:46.11 – Arkady Vyatchanin, RUS (2009)
• U.S. Open Record: 1:48.40 – Shaine Casas, USA (2022)

Final:

1. Hubert Kos (HUN) — 1:46.84
2. Leon Marchand (FRA) — 1:47.68
3. Shaine Casas (USA) — 1:49.81
4. Joshua Edwards-Smith (AUS) — 1:52.22
5. Kacper Stokowski (CLB) — 1:52.86
6. Tomoyuki Matsushita (JPN) — 1:53.29
7. Yumeki Kojima (JPN) — 1:53.61
8. Daniel Diehl (CLB) — 1:53.98