World number one and holder Dinara Safina made an early exit from the Toronto Cup on Wednesday, shocked 3-6, 6-2, 6-4 by 39th ranked Frenchwoman Aravane Rezai.
"Disaster," Safina, close to tears, told reporters. "It's not my serve, it's just my brain. I know exactly what I have to do but I am not using my brain.
"I just didn't take control of my head. I lost my temper. I had to slow down and I couldn't do the right things. I just went more and more crazy."
The victory was the first win in three visits to Canada for Rezai and earned her a small measure of revenge for the 6-1 6-0 hammering she suffered at the hands of the Russian in the French Open fourth round earlier this year.
It also marks just the second time this season that Safina has lost her opening match.
With third seed Venus Williams also stumbling out it opens up the side of the draw for two former-world number ones on the comeback trail: Maria Sharapova and Kim Clijsters.
Sharapova, working her way back to top form after nine months recovering from shoulder surgery, booked her place in the last 16 with a 6-3, 7-6 win over Austria's Sybille Bammer while Clijsters will try to join her later on Wednesday.
Fourth seeded Russian Elena Dementieva eased into the next round, dismissing Japan's Ai Sugiyama 6-3, 6-2.
She was joined by seventh seeded compatriot Vera Zvonareva who swept past Italian qualifier Roberta Vinci 6-3, 6-3 while eighth seed Caroline Wozniacki of Denmark was knocked out 7-5, 6-3 by China's Zheng Jie.
Safina got a hint she might be in for a difficult day when Rezai broke her to open the match. The Russian battled back to take the opening set before her serve began to desert her.
With the match slowly slipping away after Rezai had broken her twice in the second, a frustrated Safina called for her coach and after dropping the set summoned him again.
But there were no answers for Safina's struggles as the Russian was broken four times in the third, ending the match by smashing her racket down on to the court.
"I have a game plan, I step on to the court and do completely the opposite," lamented Safina. "Even my coach left the court because he says, 'It makes no sense sitting here because you do none of the things, so better to lose and do your own thing.'
"I step onto the court and from the first point I am empty, I am dead. I better think what's going on. I have a big tournament (U.S. Open) coming up and I have to switch my brain as fast as I can."