Melbourne, Jan 19 (IANS): Madison Keys defeated 2018 semi-finalist Elise Mertens on Saturday to advance to the round of 16 in the Australian Open.

The number 17 seed, a Australian Open semifinalist in 2015 and runner-up at the 2017 US Open, dropped just five games to make it to the second week of the tournament for the fourth time in the past five years after routing Mertens, number 12 seed, 6-3, 6-2, reports Efe news.

She hammered out 31 winners to just 21 unforced errors in the match, losing serve just once and won four of Mertens' eight service games overall.

"I think I played really well," the American said after the match.

"I served well, especially in the first set, getting out of some breakpoint situations. She played really well, which just made me raise my level," she added.

Keys won a seven-deuce third game in the first set, in which she saved three break points.

"In the second set, being able to break a couple of times and bounce back from being broken back, overall I'm just really happy with how everything went today," Keys said.

"It's definitely shaping up to be a very interesting first Grand Slam of the year. Everyone is just playing really well. Even the upsets aren't really upsets. Everyone is just playing really good tennis," she added.

Keys will now play against sixth-seeded Elina Svitolina, who downed China's Zhang Shuai 4-6, 6-4, 7-5 earlier in the day.