Bucharest Open in her home country of Romania a week later. She won the event for her second and last title of the year, defeating Roberta Vinci in the final. This helped her rise to No. 2 in the world in August. Although she was the second seed at the US Open, she was upset in straight sets by veteran qualifier Mirjana Lučić-Baroni. The next month, she withdrew from the Beijing Open in the quarterfinals due to a hip injury. She did not play another event until the WTA Tour Championships, where she qualified for the first time. Halep won two of three matches in her round robin group to advance to the knockout rounds, defeating No. 5, Eugenie Bouchard and No. 1, Serena Williams before losing her last match to No. 7, Ana Ivanovic. The victory over Williams was her first over a current world No. 1 and was also tied for the most lopsided loss of Williams' career at the time, as Halep held her to just two games. Halep won her semifinal against No. 6 Agnieszka Radwańska to set up a rematch with Williams in the final. In a complete reversal of the round robin match, Williams won the final easily, limiting Halep to just three games. Halep finished the year at No. 3 in the world, behind Williams and Sharapova. 2015: Premier Mandatory title, US Open semifinal Halep had a strong start to 2015, reaching at least the quarterfinals in her first six events. After a title in her first event of the year at the Shenzhen Open, she lost in the quarterfinals at the Australian Open for the second straight year, this time to No. 11, Ekaterina Makarova. Nonetheless, Halep rebounded to win her next two events, the Dubai Tennis Championships and the Indian Wells Open. The former was her second Premier 5 title and tenth WTA title in total, while the latter was her first Premier Mandatory title and biggest title to date. She extended her win streak to 14 matches at the Miami Open where she lost in the semifinals to world No. 1, Serena Williams. Halep did not reach any finals during the clay court season, with her best results being two semifinals at the Stuttgart Open and the Italian Open. She was two points away from advancing to the final in Rome, but could not break Carla Suárez Navarro at 5–4