|2018 Australian Open|
|Dates: 15-28 January Venue: Melbourne Park|
|Coverage: Watch highlights on BBC Two, the BBC Sport website and app. Live commentary on the best matches on BBC Radio 5 live sports extra and online.|
Top seed Simona Halep recovered from a third-round win that lasted nearly four hours to beat Naomi Osaka and reach the Australian Open quarter-finals.
The Romanian, 26, came through a tight first set before racing away to a 6-3 6-2 victory in Melbourne.
She will face sixth seed Karolina Pliskova in the quarter-final.
Pliskova, 25, beat fellow Czech and 20th seed Barbora Strycova 6-7 6-3 6-2 in a night session match lasting two hours, 41 minutes at Rod Laver Arena.
Earlier, Halep had showed no sign of the ankle injury she suffered in the first round.
"It was a great match," said Halep.
"I am really happy to be back in the quarter-finals. I didn't expect this at the start of the tournament because of the injury.
"The tournament has been a marathon for me. I am just trying to enjoy it and give everything."
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It is the third time Halep has made the last eight at Melbourne Park but the first time since 2015.
The two-time French Open runner-up is chasing a maiden Grand Slam title after securing the number one ranking last October.
Dispatching the impressive Osaka - the 20-year-old who beat Australian hope Ash Barty in the previous round - in just one hour and 19 minutes was exactly what the world number one required.
Including the three hours and 44 minutes spent defeating Lauren Davis on Saturday, Halep has spent just short of eight hours reaching the quarter-finals.
She can now enjoy the advantage of having finished her fourth-round match several hours before Strycova and Pliskova began theirs in the night session.
Osaka, ranked 72nd, had her chances in the opening set but failed to convert any of five break points.
Halep made the key breakthrough when the Japanese player leaked a forehand wide at 3-3, and an early move from Osaka in the second set was snuffed out when Halep broke back for 1-1.
The defensive skills of Halep blunted Osaka's power and the Romanian locked down the contest with just five errors in the second set, converting all three break points that came her way.