A strong day for Australia with two gold medals – Emily Seebohm winning the women’s 100 meters backstroke, and Mitch Larkin taking the men’s 100 meters backstroke. Katie Ledecky brought gold for the United States and smashed the world record in the women’s 1500 meters freestyle. James Guy produced another British gold medal in the men’s 200 meters freestyle, while Yulia Yefimova closed the day with the first Russian gold, winning the women’s 100 meters breaststroke.
Men’s 200 meters freestyle – James Guy (1:45.14) of Great Britain came from behind to stun Sun Yang and Ryan Lochte, who finished fourth, not getting enough from his unique underwater style. Guy posted the best time of the year in a crowded event, while Yang (China), with 1:45.20 won his second medal of the competition after already winning the 400 while the world record holder, Paul Biedermann of Germany, picked up the bronze, swimming a 1:45.38. Guy finished second in the 400 meters swim, behind Sun Yang.
Women’s 100 meters backstroke – Emily Seebohm finished with a 58.26, almost breaking the world record, making it a 1-2 for Australia as Madison Wilson, with 58.76, finished second to pick up silver. Mie Nielsen of Denmark, with 58.86, finished third to make it a bronze for her, while the Olympic (2012) and world (2013) champion, Missy Franklin, looked bad from the first moment and never could keep up with the rest of the group in an awful competition for her and for the Americans in general.
Women’s 1500 meters freestyle – Katie Ledecky gave the United States a second gold medal by smashing the World record, finishing at 15:25.48, improving it by 2.33. New Zealand’s Lauren Boyle got silver with a 15:40.14, while Hungary’s Boglárka Kapás took bronze, swimming a 15:47.09.
Men’s 100 meters backstroke – In a fantastic, top heavy race, Mitch Larkin of Australia won the gold medal with a 52.40, narrowly beating Camille Lacourt who swam a 52.48, while Matt Grevers of the United States took bronze with a 52.66.
Women’s 100 meters breaststroke – Yuliya Yefimova gave the Russian crowd something to cheer about with a gold medal, the first for the host nation, swimming a 1:05.66. Rūta Meilutytė was the leader after 50 meters, but got surprisingly weaker in the second leg, finishing second to pick up silver, swimming a 1:06.36, unable to defend her title from two years ago. Alia Atkinson of Jamaica wasn’t too far away, also giving Efimova a nice push in the final 50 meters, picking up bronze after posting a 1:06.42.
Adam Peaty set a new world record in the 50 meters breaststroke semifinal with a 26.42 to make it a sixth world record in the championship so far. Ledecky made it seven shortly after.
Medal Table
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 |  Australia |
3 | 1 | 1 | 5 |
| 2 |  Great Britain |
2 | 1 | 2 | 5 |
| 3 |  France |
2 | 1 | 0 | 3 |
| 4 |  United States |
2 | 0 | 2 | 4 |
| 5 |  China |
1 | 1 | 1 | 3 |
| 6 |  Russia* |
1 | 1 | 0 | 2 |
| 7 |  Hungary |
1 | 0 | 2 | 3 |
| 8 |  Sweden |
1 | 0 | 0 | 1 |
| 9 |  Netherlands |
0 | 2 | 0 | 2 |
| 10 |  Denmark |
0 | 1 | 1 | 2 |
| 11 |  Brazil |
0 | 1 | 0 | 1 |
 Japan |
0 | 1 | 0 | 1 | |
 Lithuania |
0 | 1 | 0 | 1 | |
 New Zealand |
0 | 1 | 0 | 1 | |
 South Africa |
0 | 1 | 0 | 1 | |
| 16 |  Canada |
0 | 0 | 1 | 1 |
 Germany |
0 | 0 | 1 | 1 | |
 Italy |
0 | 0 | 1 | 1 | |
 Jamaica |
0 | 0 | 1 | 1 | |
 Poland |
0 | 0 | 1 | 1 |