[1] At Wimbledon in 2008, she gained recognition when she became the first Chinese player ever to reach the semifinals of a Grand Slam singles tournament, defeating then-world No.

[2] At the end of October, she reached another WTA quarterfinal at Quebec City with a second-round win over Antonella Serra Zanetti[11] before losing in three sets to Laura Granville.

[10] Zheng started 2005 by capturing her first WTA Tour singles title at Hobart,[10] after wins over Mariana Díaz Oliva, Shinobu Asagoe, Klára Koukalová, Li Na and Gisela Dulko.

[13] She qualified for Dubai with wins over Sandra Kleinová, Maria Elena Camerin and Virginia Ruano Pascual, and went on to defeat Anabel Medina Garrigues in the main draw, before succumbing to Lindsay Davenport.

[13] But Zheng remained in fine form, and reached her second WTA Tour final at Rabat, Morocco in May, losing to Nuria Llagostera Vives[10] after wins over Catalina Castaño, Maureen Drake and Tathiana Garbin,[13] followed by a walkover against Na Li who had to retire at 3–3 from an ankle sprain.

[citation needed] A three-set loss to Francesca Schiavone in the first round of the French Open prevented Zheng from defending her ranking points accrued there the previous year.

[13] In August, she reached the second round at Los Angeles by again beating Shinobu Asagoe, the Canadian Open quarterfinal (with wins over María Emilia Salerni and Ai Sugiyama), and another quarterfinal at New Haven (after defeating Katarina Srebotnik and Émilie Loit in qualifying, and Jamea Jackson in the main draw, though she was assisted by entering the tournament with a first-round bye and as a lucky loser in the final round of qualifying to Jelena Kostanić).

[13] Further first-round wins in September over María Vento-Kabchi (at Bali) and Jelena Janković (at Beijing) could not be consolidated on in subsequent rounds of the respective tournaments;[13] but at Guangzhou, the last tournament she would play all year, she reached the semifinal with wins over Carly Gullickson, Jamea Jackson and Maria Kirilenko,[13] before suffering her second loss of the year to Nuria Llagostera Vives.

[14] However, after a first-round loss in Indian Wells, her 2006 singles breakthrough came at Key Biscayne where she reached the quarterfinals with wins over Nathalie Dechy and Anna-Lena Grönefeld before falling to Tatiana Golovin.

[14] Zheng's newfound confidence earned a title at her next tournament in Estoril, where she defeated top-seeded Flavia Pennetta en route to the final[14] before a victory over compatriot Li Na who was forced to retire at one set each.

She ended up winning the gold medal, with victories over Shikha Uberoi, Chan Yung-jan, Aiko Nakamura, and Sania Mirza.

[2] At the Australian Open, Zheng put in an extremely disappointing performance, losing to then 97th ranked Julia Schruff of Germany, after holding match point on more than one occasion.

She donated her prize money from the tournament and spent time helping the victims and post-reconstruction effort of the 12 May earthquake that killed nearly 70,000 people and left five to ten million homeless in her home province Sichuan.

[23] Based on her strong China Open performance, Zheng became Asia's highest ranked women's singles player at world No.

In the doubles event, she and her partner Yan Zi were eliminated in the third round, by Nuria Llagostera Vives and María José Martínez Sánchez.

At the Birmingham Classic, the first tournament on grass, Zheng was the top seed but lost to the eventual champion Magdaléna Rybáriková in the third round.

After three-set wins over Peng Shuai, María José Martínez Sánchez and Marion Bartoli, as well as a straight sets fourth-round win over Alona Bondarenko, Zheng made Australian open history by becoming the first Chinese player to reach an Australian Open semifinal when she took out unseeded Maria Kirilenko in the quarterfinals.

In consolation, Zheng partnered with Maria Kirilenko to win her second doubles title of the year, defeating second seeded Lisa Raymond and Rennae Stubbs in the final.

Zheng then played at Eastbourne, qualifying for the main draw by beating Ayumi Morita, Edina Gallovits-Hall, and finally Melanie Oudin.

At Wimbledon, Zheng reached the second round for the third consecutive year, beating Zuzana Ondrášková, before losing in disappointing fashion to Japanese qualifier Misaki Doi, 3–6, 1–6.

In doubles, Zheng and Peng reached the quarterfinals, losing a tight three-set match to eventual champions Květa Peschke and Katarina Srebotnik.

In the next qualification round, Zheng faced Japanese veteran Kimiko Date-Krumm for the first time, and by winning that match in three sets, she qualified for the main draw.

In the first round of the main draw, Zheng waltzed past fellow qualifier Alberta Brianti 6–2, 6–1, setting up a second-round match with second seed Kim Clijsters.

She amazingly won her first match versus Zuzana Kučová 6–1, 6–1 and after that she beat fifth-seeded Australian Jarmila Gajdošová to reach the quarterfinals, which had to be postponed because of rain.

At the Australian Open, Zheng reached the fourth round, where she was beaten by Sara Errani, with straight sets wins over Madison Keys, Roberta Vinci and top-10 ranked Marion Bartoli.

Zheng then reached the third round at the Miami Open, beating Hradecká and Angelique Kerber in straight sets, before losing to Dominika Cibulková, 2–6, 0–6.

Zheng then lost in the first round of Madrid, Rome and Brussels to Maria Kirilenko, Anabel Medina Garrigues and Arantxa Rus, respectively.

She chose to begin the grass-court season in Birmingham, however as she registered late she was forced to qualify for the main draw, which she did by beating both Natalie Grandin and Sandra Zaniewska.

She wore down Venus Williams with powerful returns and impressive endurance, eventually winning a third-set tiebreaker to take the match, but she then lost to Carla Suárez Navarro in the third round.

However, at the same tournament, she and her partner Chan Yung-jan reached the finals of the women's doubles event, where they were defeated by Bethanie Mattek-Sands and Lucie Šafářová in straight sets.