Simona Halep plays a backhand return to Japan's Naomi Osaka in their fourth round clash yesterday. Pic/AFP

World number one Simona Halep eased into the quarter-finals of the Australian Open yesterday with a 6-3, 6-2 victory over unseeded Naomi Osaka of Japan in 81 minutes. "I'm really happy that I'm back in the quarter-finals," said the Romanian, who last made it this far in 2015 and has been nursing a troublesome ankle that she rolled in her first-round match.'