The following year, Kvitová reached the semifinals of the Australian and French Opens, falling on both occasions to Sharapova. She also made the quarterfinals at the Wimbledon Championships, where she was the defending champion, but fell to eventual champion Serena Williams. Partnering Tomáš Berdych, they won the Hopman Cup, giving the Czech Republic its second Hopman Cup title. She also reached the last eight at the Summer Olympics and was also crowned the US Open Series champion after winning titles in Montreal and New Haven. Kvitová ended 2012 as world No. 8. Highlights of Kvitová's 2013 season include winning titles in Dubai and Tokyo, along with quarterfinal and semifinal appearances at the Wimbledon Championships and WTA Tour Championships, respectively. She finished 2013 as world No. 6.