Serena Williams marched into the Australian Open Last 16 on Saturday and warned she was still improving after taking time out to console the latest victim of her quest for a record-equalling 24th major.

Serena swatted aside Ukrainian teenager Dayana Yastremska 6-2, 6-1 in a Melbourne Park mauling that reduced the World No. 57 to tears. Serena, 37, who is in the hunt for her first Grand Slam since having a baby, comforted the youngster at the net, telling her: "You did amazing, you're gonna make it, don't cry".