Ruthless Halep races into Australian Open quarter-finals

Two-time Grand Slam champion Simona Halep surged into the quarter-finals of the Australian Open on Monday with a straight-sets victory over 16th seed Elise Mertens.

The fourth seed won 6-4 6-4 and plays Estonian 28th seed Anett Kontaveit or unseeded Polish teenager Iga Swiatek in the last eight in Melbourne.

Former world number one Halep, beaten in the 2018 final by Caroline Wozniacki, has not dropped a set in four matches in Melbourne and the Romanian looks in ominous form.

With her win, the 28-year-old will rise from third to second in the rankings.

"I had to calm myself down because when I get a little bit nervous I get crazy on court so I had to stay cool, to get energy from the box and play without looking back," she said, after some anxious moments in the second set.

After top seed Ashleigh Barty, Halep -- last year's Wimbledon champion and a former French Open winner -- is the highest remaining seed left in the draw.

Second seed Karolina Pliskova, holder and third seed Naomi Osaka, and history-chasing Serena Williams were among six top-10 seeds who lost in the third round.

Halep defeated Belgium's Mertens in two of their three previous meetings, including in the last 16 of the French Open in 2018, when she went on to win the title.

But Mertens prevailed the last time they met when she came from a set down in the final in Doha last year.

Halep drew first blood at a sunny Rod Laver Arena when she broke Mertens at the fourth break-point opportunity and consolidated for a 3-1 lead.

The 24-year-old Mertens, whose best performance at a Grand Slam came in reaching the Australian Open semi-finals in 2018, broke back and then stubbornly held serve for 4-3.

But Halep broke again for 5-4 and converted the fourth set point when Mertens put a forehand into the net.

The Romanian began the second set with intent, breaking for another early lead, but Mertens would not go quietly, breaking back as she piled on the pressure.

The ninth game proved pivotal, as Halep finally got the break at the fifth opportunity before serving out the match.