Women's 50m Butterfly
Sarah Sjöström claimed her sixth world title and her second in the women's 50m butterfly.
Sjöström became the second female swimmer to retain her world title in this event. Inge de Bruijn (NED) triumphed in this event in 2001 and 2003.
Sjöström joined De Bruijn as the only female swimmers to win this event twice at world championships.
All six of Sjöström's world titles have come in butterfly events.
Sjöström also won the 100m fly in Budapest, meaning that she completed the 50m-100m butterfly double at the same world championships. Two years ago in Kazan, Sjöström had already become the first female swimmer to ever achieve this.
Sjöström pocketed her 11th career medal at world championships (G6-S4-B1).
Ranomi Kromowidjojo (NED) won her 14th career world championship medal and her second in a butterfly event, following bronze in the 50m fly in Barcelona in 2013.
Farida Osman (EGY) became the first swimmer from Egypt to collect a world championship medal (bronze).
Men's 50m Freestyle
Caeleb Remel Dressel (USA) picked up his fourth gold medal at the 2017 World Aquatics Championships by emerging victorious in the men's 50m freestyle. He would later add his fifth and sixth.
The 20-year-old American had already struck gold in the men's 100m freestyle, the men's 4 x 100m freestyle relay and the mixed 4 x 100m medley relay.
Dressel became the fourth male swimmer to complete the 50m-100m freestyle double at the same world championships. Aleksandr Popov (RUS) accomplished this feat in 1994 and 2003, Anthony Ervin (USA) matched him in 2001 and Cesar Cielo Filho (BRA) followed them up in 2009.
At 20, Dressel was the youngest of the eight swimmers that entered the final in this event.
Benjamin Proud (GBR) claimed a bronze medal in this event after taking gold in the men's 50m butterfly.
Bruno Fratus (BRA) improved on his bronze medal in this event from Kazan two years ago. This had been his only world championship medal in an individual event until today.
Women's 200m Backstroke
Emily Seebohm (AUS) joined Cornelia Sirch (GDR), Kirsty Coventry (ZIM) and Missy Franklin (USA) on a record two world titles in this event.
She also picked up Australia's first gold medal in swimming events at these world championships.
Australia have now won at least one gold medal in long course swimming at each World Aquatics Championships following their duck in 1986.
Katinka Hosszú claimed her 12th career world championship medal and her first silver in the competition (G6-S1-B5).
Hosszú (silver) became the second woman to grab a medal in the 200m backstroke in front of a home crowd, after Lorenza Vigarani (ITA) who finished third in Rome in 1994
Kathleen Baker (USA) picked up United States' 12th medal in this event, extending the record (East Germany next, 6).
United States have now claimed a medals in the women's 200m backstroke at the last eight world championships.
Men's 100m Butterfly
Caeleb Remel Dressel (USA) became the first male swimmer to win both the men's 100m freestyle and the men's 100m butterfly at the same world championships.
Dressel won his fifth gold medal at the 2017 World Aquatics Championships after having won his fourth in the men's 50m freestyle earlier on the night. He would later add a sixth.
Kristof Milak (HUN) claimed Hungary's third successive silver medal in this event, after László Cseh (HUN) finished second in 2013 and 2015.
These are Hungary's only medals in the men's 100m butterfly.
Swimmers representing United States have combined for 10 of 17 available world titles in this event. Apart from the US, South Africa (2) is the only country to have won this more than once.
Joseph Schooling (SGP) claimed a bronze medal in this event, just like two years ago in Kazan, when he became the first swimmer from Singapore to win a world championship medal.
James Guy (GBR) shared the bronze with Schooling and became only the second swimmer representing Great Britain to claim a medal in this event following Andy Jameson (GBR) in 1986.
Women's 800m Freestyle
Katie Ledecky (USA) won her fifth gold medal at the 2017 World Aquatics Championships, after having already triumphed in the women's 400m and 1500m freestyle, the women's 4 x 100m freestyle relay and the women's 4 x 200m freestyle relay.
With her fifth gold medal at a single world championships, Ledecky equalled a personal best, from two years ago in Kazan. The only female swimmer to ever win more was Missy Franklin (USA) in Barcelona in 2013.
Ledecky became the first woman to win this event three times at the world championships.
The only other women that claimed three medals in this discipline are Kate Ziegler (USA, G2-S0-B1), Lotte Friis (DEN, G1-S2-B0) and Diana Munz (USA, G0-S3-B0).
Ledecky became the first woman to win the 800m freestyle for the fifth consecutive time at the Olympic Games and world championships combined. Ledecky had shared the record of four with Janet Evans (USA) who won Olympic gold in 1988 and 1992 and the world title in 1991 and 1994.
Mixed 4 x 100m Freestyle Relay
Caeleb Remel Dressel (USA) became the first person to win three gold medals on one day at the world championships. Earlier on the night, he won gold in the men's 50m freestyle and the men's 100m butterfly.
Dressel has now won six gold medals at the 2017 World Aquatics Championships. He is the third man to win this many at a single world championships. Michael Phelps (USA) won seven events in 2007 and Ian Thorpe (AUS) won six in 2001.
Mallory Comerford (USA) and Simone Manuel (USA) won their fourth gold medal at these world championships.