Djokovic, Zverev reach Australian Open quarters

Novak Djokovic trampled all over Czech 24th seed Jiri Lehecka to seal a 6-3 6-4 7-6(4) win on Sunday and book a blockbuster clash with Carlos Alcaraz in the Australian Open quarter-finals, while World number two Alex Zverev overcame a mid-match wobble to beat Ugo Humbert 6-1 2-6 6-3 6-2.

After a couple of tough early tests, Djokovic sharpened his tools in his hunt for a record 25th Grand Slam crown and 11th at Melbourne Park with a mauling of Czech Tomas Machac in the last round and was again at his impressive best against Lehecka.

"Thank you very much for being here tonight. I appreciate your presence and the support. I'll see you in the next round. Thank you very much," Djokovic said curtly on court before signing a few autographs and heading to the dressing room.

A solitary break in the eighth game was all Djokovic needed to take the opening set, as the 37-year-old Serb looked in total control despite playing well within himself in perfect conditions at a packed Rod Laver Arena.

Seventh seed Djokovic attacked Lehecka's serve early in the next set and efficiently doubled his advantage in the match, as the 23-year-old Czech was left with a mountain to climb to equal his feat of reaching the quarter-finals two years ago.

A rejuvenated Lehecka recovered after dropping serve again and stayed in the fight to frustrate Djokovic in the third set, but there was only going to be one winner when the Serb went ahead 4-2 in the tiebreak.

With Djokovic's forehand and serve clicking back into gear, he comfortably closed out the win to equal his now retired rival Roger Federer's all-time record of 15 appearances in the last-eight stage of the Melbourne Park major.

Alexander Zverev was knocked off his stride in the second set by the left-handed Frenchman, who he beat soundly in the final of the Paris Masters last year.

But the rangy German found solace in his serve and finished the match in a hail of winners to set up a quarter-final with American Tommy Paul.

"He's an incredibly tough player," Zverev said of 14th seed Humbert.

"I think in the last few months he did so many steps forward.

"He has a big chance of becoming a top 10 player soon. Incredible player, incredible match and I'm happy to be in the quarter-finals only losing one set."

Zverev started superbly against Humbert, serving up a storm and blasting winners for fun to break the Frenchman three times in a 22-minute first set.

But there was not a hint of concern from Humbert's side of the court.

The stolid 26-year-old simply pressed the reset button and turned the match at 2-2 in the second set, smashing through Zverev's defences after five break points in a thrilling game.

Rattled, Zverev dropped serve a second time before Humbert levelled the match with a wide serve that beat Zverev's backhand.

The match swung again as Zverev shored up his defence and Humbert wavered on serve after nine games of near-flawless tennis.

Breaking Humbert to lead 5-3 with a sharp crosscourt return, Zverev served out the third set to love.

There was no third wind for Humbert, though, as he dropped serve again with an unforced error to trail 3-1 in the fourth set.

Though Humbert had a chance to level serve at 3-2 after earning a break point with a ferocious forehand passing shot, Zverev produced an imperious second serve down the 'T' to cancel the threat.

He followed up with another backhand rocket on return to break Humbert again on the way to a win that suggested he is well recovered from a bicep injury that impacted his preparations.

"A week ago I was very unsure of my level and very unsure of my tennis," he said.

"I couldn't really prepare the way I wanted to...but I definitely want to play three more matches here, so we'll see how that goes."