SHANGHAI (Reuters) - Fourth seed Stan Wawrinka continued to struggle for late-season form after the Australian Open champion crashed out of the Shanghai Masters in the second round on Wednesday, going down 5-7 7-5 6-4 to Gilles Simon.
Wawrinka fell at the first hurdle in Tokyo last week and, after receiving an opening round bye, the Swiss repeated the feat in Shanghai despite breaking Simon's serve in the 12th game of the match to claim the opening set.
His 29th-ranked French opponent refused to buckle, however, battling back to tie the contest before overcoming an early break in the decider to emerge victorious after two and a half hours.
With five spots at the season-ending ATP World Tour Finals still up for grabs, David Ferrer boosted his chances of making the London event by surviving a tense second round encounter against Martin Klizan, who served for the match in the second set, to progress.
The fifth seeded Spaniard found the going difficult against his Slovak opponent before grinding out a 4-6 7-6(4) 6-4 victory as he looks to climb up from his current 10th position in the race for one of the eight spots at the November tournament.
World number 553 Chuhan Wang's ATP World Tour debut was halted in another second round encounter when Tunisia's Malek Jaziri beat the Chinese wildcard, who had stunned 15th seed Fabio Fognini in the first round, 6-0 6-4.
The top three in ATP world rankings -- Novak Djokovic, Rafa Nadal and Roger Federer -- open their Shanghai Masters campaigns later on Wednesday.
(Reporting by Amlan Chakraborty; Editing by John O'Brien)