Petra Kvitova, the 21-year-old Czech left-hander who caused a sensation by winning Wimbledon as an outsider four months ago, proved she is now a fully fledged member of the sport’s elite by winning the WTA (year-end) Championships. Kvitova did that with a 7-5, 4-6, 6-3 win over Victoria Azarenka, the fourth-seeded Belarussian, which earned her the second most important title of her career and further enhanced her growing reputation. It also gained her a career-high year-end ranking of world number two – a tremendous surge from the 30th place at which she began 2011.