Leander Paes and Elena Vesnina have advanced into the quarter finals of the mixed doubles event at the Wimbledon Tennis Championships. The Indo-Russia pair defeated Ashley Fisher of Austria and Mona Barthel of Germany 6-3, 6-3 in a second round clash in London yesterday. Paes and Vesnina face Belarussian pair of Max Mirnyi and Victoria Azarenka in the next round.Meanwhile, Roger Federer of Switzerland and Serbia's Novak Djokovic have stormed into the men's singles semi-finals.