World number one and top seed Angelique Kerber suffered an unexpected defeat to Estonian qualifier Anett Kontaveit in the second round of the Internazionali BNL d'Italia in Rome.

Andy Roddick produced the shock of the Sony Ericsson Open by knocking world number three Roger Federer out at the third-round stage with a 7-6 (7/4) 1-6 6-4 win.