Michael Phelps eased his World championships heartache with a 100m butterfly win on Saturday as 16-year-old Melissa ‘Missile' Franklin exploded onto the scene with another two gold medals in Shanghai.
Drug-row Brazilian Cesar Cielo earned his second sprint title and Olympic champion Rebecca Adlington broke Britain's gold medal duck in the women's 800m, as Franklin helped the United States win their first 4x100m medley in more than a decade.
Phelps, the World and Olympic champion and World record-holder, was third halfway through the 100m butterfly but he swept through the field to win in 50.71s, ahead of Poland's Konrad Czerniak and America's Tyler McGill.
With nemesis Ryan Lochte watching from the stands, Phelps extended his record number of World titles to 25, including three in Shanghai, alongside two silver medals and one bronze.
“I'm not in the right shape physically. I want to be faster. It's a tough race,” Phelps said.
Phelps returned to China looking for a possible seven gold medals, to follow his eight from the 2008 Olympics, but he was beaten by Lochte in the 200m freestyle and again in the 200m individual medley, where his team-mate set a World record.
The United States also enjoyed yet more success through teenager Franklin, who claimed her second individual title and then anchored the medley victory to make it five medals overall.
Franklin, one of the leading stars of Shanghai, was never behind in the 200m backstroke and she won it convincingly in 2m 5.10s ahead of Australia's Belinda Hocking and Sharon van Rouwendaal of the Netherlands.
And the teenager was reliable again in the medley, as the United States held off host China and Australia to claim its first World title since 1998.
In other races, Dutch swimmer Inge Dekker upset a field including the World record-holder and defending champion to win the women's 50m butterfly and claim her first individual World title.
And in the women's 800m, Britain's Adlington timed her final burst to perfection as she overtook front-runner Lotte Friis in the closing stages to win it in 8m 17.51s, with America's Kate Ziegler third.
Earlier, the controversial Cielo successfully defended his 50m freestyle world title as the sport's chiefs criticised doping rules after a case involving the Brazilian.
The Olympic champion and World record-holder's victory never looked in doubt as he surged down the Sea Crown stadium pool to touch in 21.52sec ahead of Italy's Luca Dotto and French swimmer Alain Bernard.
The results:
Men: 50m freestyle: 1. Cesar Cielo (Bra) 21.52s, 2. Luca Dotto (Ita) 21.90, 3. Alain Bernard (Fra) 21.92.
100m butterfly: 1. Michael Phelps (USA) 50.71, 2. Konrad Czerniak (Pol) 51.15, 3. Tyler McGill (USA) 51.26.
Women: 50m butterfly: 1. Inge Dekker (Ned) 25.71, 2. Therese Alshammar (Swe) 25.76, 3. Melanie Henique (Fra) 25.86.
200m backstroke: 1. Melissa Franklin (USA) 2m 5.10s, 2. Belinda Hocking (Aus) 2:06.06, 3. Sharon van Rouwendaal (Ned) 2:07.78.
800m freestyle: 1. Rebecca Adlington (GBr) 8:17.51, 2. Lotte Friis (Den) 8:18.20, 3. Kate Ziegler (USA) 8:23.36.
4x100m medley: 1. U.S. 3:52.36, 2. China 3:55.61, 3. Australia 3:57.13.
