Peng Shuai becomes only third Chinese player to reach a grand slam semifinal . Unseeded 28-year - old beats teen Belinda Bencic , next seeded Caroline Wozniacki . Peng underwent major heart surgery aged 12 to pursue tennis career . Peng said on court after her 6-2 6-1 victory , earning a round of applause after pausing as emotion got the better of her . ` Five - time men 's champion Roger Federer through to quarterfinals .
Peng Shuai becomes only third Chinese player to reach a grand slam semifinal . Unseeded 28-year - old beats teen Belinda Bencic , next seeded Caroline Wozniacki . Peng underwent major heart surgery aged 12 to pursue tennis career . Five - time men 's champion Roger Federer through to quarterfinals .