Garbine Muguruza upbeat after quarter-final exit

French Open quarter-finalist Garbine Muguruza was pleased despite failing to surpass her efforts at Roland Garros from 12 months earlier.

Muguruza burst onto the WTA Tour in 2014 with a run to the Australian Open fourth round followed by a last-eight appearance in Paris, and she has begun her '15 season in identical fashion.

Her '14 run at the clay-court major was signposted by a 6-2 6-2 dismissal of Serena Williams, and a strong performance against eventual champion Maria Sharapova - Muguruza led 6-1 5-4 in their quarter-final, but won just one game thereafter.

In 2015, Muguruza met her match in the form of 13th seed Lucie Safarova, the left-handed Czech progressing 7-6 (7-3) 6-3.

Muguruza said she was stressed early in her campaign in the French capital, which saw the 21st seed defeat Petra Martic, Camila Giorgi, 11th seed Angelique Kerber and 28th seed Flavia Pennetta to reach the second week.

"When I started I was a bit stressed, I didn't really know what to expect," the 21-year-old said via a translator.

"But I'm very happy because these are my best results.

"I would have liked to have gone deeper in the tournament, but now I've managed to overcome the stress I had during the first two rounds so I'm quite happy."

Muguruza hailed Safarova's serve, which won the Czech 72 per cent of points behind her first ball.

"I'm not... jumping with joy, but I'm quite happy because I fought until the very end," she said.

"But Safarova played so well that I couldn't manage, it was impossible.

"I have the impression that she was running well, her serve was fantastic, and this time, I couldn't win."

Ominously, Muguruza claimed she has improved in the 12 months since dethroning Williams at Roland Garros - and said her mental application was not at fault for her defeat.

"I think that last year, I had the impression I had not played my best tennis, whereas this time I played my best," she said.

"It was not a mental thing this time.

"There were two key moments when I was returning, and unfortunately, I couldn't return the way I wanted. The wind was blowing hard against me, and that's when she won a few points.

"It had nothing to do with my mental condition."