Samantha Stosur’s 6-3 7-6(7) defeat of Spain’s Maria Jose Martinez Sanchez in the Indian Wells quarterfinals ended in controversy, as Stosur appeared to make a late challenge of a Martinez first serve at 7-6 in the tiebreaker after she missed a backhand return down the line.

Martinez argued the challenge to chair umpire Kader Nouni, but to no avail. The bewildered Spaniard then double faulted to lose the match.

“It was confusing,” Martinez said. “When I served and he say that it was out, I thought it was 8-all. And then she asked for the challenge, but I don't know why I was thinking it was 8-All, and I do the first serve.

"He told me that he didn't know if she ask for challenge for the serve or for her return. I think that it was too late, but said no. It was disappointing.  I don't know what happened.”

Stosur said she was planning to challenge immediately.

“I thought the serve was a fault, so as soon as the ball came off my racquet I tried to challenge,” the Aussie said. “I guess the umpire didn't know what shot I was challenging, but I always wanted to challenge that serve.

"Then obviously there was a little bit of confusion after the fact. Obviously it's a little bit more big a deal because it was match point.  But I thought that's the way it would happen no matter what the score. Unfortunately that can happen with tennis.”—Matthew Cronin