Jelena Jankovic (Serbian: Jelena Janković, Serbian Cyrillic: Јелена Јанковић, Serbian pronunciation: [ˈjɛlɛna ˈjaːnkɔvitɕ]; born February 28, 1985 in Belgrade) is a former World No. 1 Serbian professional tennis player. She has reached one Grand Slam final and is currently ranked World No. 7.
Janković learned her first tennis skills in Tennis Club 'Red Star'. As a nine-and-a-half year old she was introduced to tennis by her elder brother and fitness coach Marko. She was later trained at the Tennis Academy of Nick Bollettieri. As a junior she won the 2001 Australian Open. In 2001, she started to play on the WTA Tour; she reached the second round at her first tournament at the Indian Wells Masters.
In October 2003, Janković entered the top 100 at No. 90 for the first time after winning her first ITF title in Dubai. Three months later, Janković garnered her first top 10 win against Elena Dementieva 6–1, 6–4 in the first round of the 2004 Australian Open. In May, Janković won her first WTA title, a Tier V event, in Budapest, defeating Martina Suchá in the final 7–6, 6–3. Following her win in Budapest, she reached No. 51 in the world. Elsewhere in her 2004 season, she defeated top 20 players Nadia Petrova (twice), Vera Zvonareva, Patty Schnyder and Paola Suárez. Janković finished 2004 ranked No. 28 in the world.
She was ranked World No. 1 for seventeen consecutive weeks until she was overtaken by Serena Williams on February 2, 2009. She was the year-end World No. 1 in 2008, the first player in the history of the WTA tour to do this without winning a Grand Slam title. As of August 3, 2009, she is ranked World No. 5.
Janković has reached the singles final of the US Open and the singles semifinals of the Australian Open and the French Open. In 2007, she became the first Serbian player to win a Grand Slam Title when she won the Wimbledon mixed doubles title with British partner Jamie Murray.
Source : Wikipedia.com