Dizzy Spells Doom Eugenie Bouchard, Jo-Wilfried Tsonga at China Open

Eugenie Bouchard's concussion nightmare extended into the China Open on Monday as she felt faint and tearfully retired in the first round -- shortly after Jo-Wilfried Tsonga was also struck by dizzy spells.

Bouchard has not played since she slammed her head in a locker-room fall at the US Open, and she lasted just 10 games against Andrea Petkovic before feeling dizzy and having her blood pressure checked.

The Canadian sobbed into her towel and was comforted by Petkovic before she rose and walked out, waving grimly to the Beijing crowd, with the scoreline standing 6-2, 1-1 to her opponent.

"I just asked her what happened, and she told me that she felt very dizzy. Then I asked if it was the same, if it still was the concussion," Petkovic said.

"She said, yeah, it tends to come back when she gets physically very active. I just said I feel it's really bad luck because I thought she was playing so well again."

Earlier Tsonga refused to blame Beijing's notorious air pollution as he was also hit by dizzy spells before falling at the first hurdle 7-6 (7/4), 6-2 to little-known Austrian Andreas Haider-Maurer.

Tsonga was down in the second set when he staggered on court and took a time-out, during which he had his heartbeat checked with a stethoscope and was given medication.

But it was not long before the out-of-sorts Tsonga limply succumbed to Haider-Maurer, who at world number 64 becomes the lowest ranked player to beat the Frenchman this season.

The Chinese capital's air pollution was in the "very unhealthy" range on Monday but eighth seed Tsonga said he did not know if that was what caused his problem.

"I don't know. You know, nothing in me can calculate if it's enough oxygen for me or not. I just play tennis. Today I had an opponent, he was just better than me today," he shrugged.

"I was like, dizzy. It came just like this, on one run. After one run, I went back to play a return and I feel a little bit dizzy. But I hope it's nothing important," Tsonga added.

The departures of Tsonga and Bouchard come after women's top seeds Simona Halep and Petra Kvitova, troubled by injury and illness, both exited on Sunday.

The tail-end of the season has seen a series of retirements and withdrawals, including Serena Williams' decision to rest until next year. Maria Sharapova is also sidelined from Beijing with injury.

World number one Novak Djokovic, unbeaten in five appearances, heads the men's draw while third seed Flavia Pennetta, the US Open champion, is now the on-paper favourite among the women.