MADRID (Reuters) - World number one Serena Williams crashed out in the third round of the Madrid Open when she lost 4-6 6-2 6-3 to Russian Nadia Petrova on Wednesday.

A pumped-up Petrova ground her opponent into submission, constantly hitting the lines, and Williams appeared to have given up the ghost well before she sent a forehand over the baseline on the Russian's first match point.

(Reporting by Iain Rogers, editing by Pritha Sarkar)