SHANGHAI (AFP) - Olympic hosts Britain struck gold at the world aquatics championships Tuesday as China bagged another two diving titles to stand just four away from sweeping all 10. Britains Keri-Anne Payne was overjoyed with her win in the womens 10km open water event, which ratcheted up hopes she can improve on her 2008 Olympic silver medal at the London Games next year. With the victory, ahead of Italys Martina Grimaldi and Marianna Lymperta of Greece, Payne became Team Britains first confirmed athlete for London 2012 with the top 10 finishers all gaining automatic entry. I really wish I could swear right now, but Im not that kind of person, said Payne. To be on the Olympic team, and then its a home Olympics as well, Im so absolutely pleased. But it was Chinas unstoppable divers who again snatched the spotlight when they added the womens 1m springboard and mens 3m synchro titles to take their total to six at the purpose-built Crescent Lagoon venue. Olympic and world champion Qin Hai and partner Luo Yutong swept to victory in the mens event, after Shi Tingmao led a Chinese one-two in the womens competition a supposed weak spot for the hosts. Russias Ilya Zakharov and Evgeny Kuznetsov took silver and Yahel Castillo and Julian Sanchez of Mexico won bronze in the mens 3m, as Chinas challengers continued to come up short at the first world championships hosted by the giant country. Chinas Wang Han was second behind Shi in the womens 1m, with Tania Cagnotto of Italy finishing in the bronze medal position. In the championships first open water event, held under scorching sun at Jinshan City Beach, Payne broke ahead of the pack early and stayed there to win in 2hr 1min 58.1sec, 1.8 sec ahead of Grimaldi. Through the whole race I tried to make it as easy as I could so that I knew if anyone did attack, I still had a bit left in me, said the Briton. Australian Melissa Gorman, Argentinas Cecilia Biagioli, Brazils Poliana Okimoto, Czech Republics Jana Pechanova, Angela Maurer of Germany, Swiss Swann Oberson and Spains Erika Villaecija Garcia also won Olympic berths. Natalie Du Toit of South Africa, who became the first female amputee to compete in an able-bodied Olympics in 2008, placed 39th. Du Toit, who has no lower left leg, finished in 2:08:27:1. On day four, China lead the medals table with their six diving golds, followed by Russia with their two titles in synchronised swimming. Water polo competition is also under way at the 16-day, biennial championships, with the blue-riband pool swimming events kicking off on Sunday. But the tournament has opened under a cloud with the Court of Arbitration for Sport due to announce this week whether it will impose a doping ban on Brazilian swim star Cesar Cielo, who tested positive for a banned diuretic.