'Big Four' through as Sharapova sinks in Melbourne

MELBOURNE (Reuters) - Rafa Nadal came through his first proper test to storm into the quarter-finals of the Australian Open on Monday but Maria Sharapova was ushered to the exit after a second big shock in as many days in the women's draw.

Victoria Azarenka was left as the only top-three seed still standing in the last eight when Sharapova was scratched from the title race by Dominika Cibulkova, a day after Serena Williams had also tumbled out in the fourth round.