One contentious point, after five hours and five sets, had Pablo Carreno Busta screaming at the umpire and gave Kei Nishikori the shift in momentum he needed to clinch his place in the Australian Open quarterfinals.

After being two points from victory, Carreno Busta lost five straight, including that one in the last tiebreaker where he berated the chair umpire for not ruling a replay, allowing Nishikori to advance 6-7 (8), 4-6, 7-6 (4), 6-4, 7-6 (8).

It was the second time the 2014 U.S. Open finalist has had to come back from two sets down in the tournament, and the second time he's had to win in the new 10-point fifth-set super tiebreakers that were introduced at Melbourne Park this year.

"That was important point, too, but, I mean, you should ask how I came back from two sets down," Nishikori said Monday. "That was only one point. I mean, maybe affect him, but ... maybe it could affect me."

Maybe affect Carreno Busta? The 27-year-old Spaniard lost it, stopping only briefly to hug Nishikori after the match before slamming his bag onto the court and screaming again at the umpire as he left Margaret Court Arena.

"I left as soon as I could after the last point, because I knew I might explode," Carreno Busta said in Spanish. "I apologize for the way I left the court."

On the disputed 14th point, Carreno Busta's shot clipped the net and bounced on the left line. Nishikori readjusted quickly and hit an easy backhand winner.

A line judge called "out" as Nishikori hit the ball, and Carreno Busta was nowhere close to playing it. But Carreno Busta challenged the decision, and Hawk-Eye showed his ball hitting the line. The point remained with Nishikori, however, because chair umpire Thomas Sweeney ruled neither player had been hindered in the point.

Carreno Busta didn't win another point, and Nishikori sealed the match with an ace. The eighth-seeded Nishikori stays to play six-time Australian Open champion Novak Djokovic. Carreno Busta is out of the tournament.

"It's tough, to me to leave Australian Open like this, because I think that I played an unbelievable match," the 23rd-seeded Spaniard said. "Also Kei, he played really good, and that's sad to leave like this."

Nishikori had an earlier chance to serve out at 5-4 in the fifth, but Carreno Busta broke and it went down to the wire again.

"I'm really glad how I came back — I don't even know how I come back," said Nishikori, who has nearly 14 hours on court in four rounds. "Yeah, there were many tough moments."

In the last match of the round, Djokovic overcame a couple of tumbles to the court and a series of energy-sapping baseline exchanges — one point lasted 42 shots — to beat No. 15 Daniil Medvedev 6-4, 6-7 (5), 6-2, 6-3 and return to the quarterfinals for the first time since 2016.

Djokovic joked during an on-court interview: "Since I guess my next opponent is watching, I'm feeling fantastic. I've never felt fresher in my life."

He later said he had a few aches and pains and "I didn't feel so great in the last 20 minutes."

"We'll see tomorrow how the body reacts (but) I'm confident I can recover and can be ready for the next one."

No. 16 Milos Raonic and No. 28 Lucas Pouille, who ousted No. 11-seeded Borna Coric 6-7 (4), 6-4, 7-5, 7-6 (2), will meet in the other quarterfinal on the top half.

Raonic's consistent winners frustrated fourth-seeded Alexander Zverev to the point where he shattered his racket and got an umpire's warning in the 6-1, 6-1, 7-6 (5) defeat.

The big-serving Canadian had his serve broken in the opening game but responded by winning the next eight games until Zverev finally held. After falling behind 4-1 in the second, Zverev slumped in his courtside chair and smacked his racket into the court eight times before tossing it aside.

The angry outburst only served to highlight Raonic's dominance.

"I played incredible today," the 2016 Wimbledon runner-up said. "I did a lot of things very well. Proud of that."

Zverev, on the other hand, apologized after failing again to break his drought against top-20 ranked men at the majors.

"I was very angry, so I let my anger out," he said. "I played bad. The first two sets especially I played horrible.

"It's just tough to name one thing. I didn't serve well, didn't play well from the baseline. Against a quality player like him, it's tough to come back from that."

Czech Petra Kvitova is aiming to rock Japan's Naomi Osaka with an early onslaught in the Australian Open final, predicting the decider will be more slugfest than tactical masterclass.

The final on Saturday features two of the game's biggest hitters in a showdown for both the Australian crown and the world number one ranking.

Two-time Wimbledon champion Kvitova is on an 11-match winning streak and has been in imperious form at Melbourne Park, where she is yet to drop a set or even be stretched to a tie-break.

The 28-year-old is jubilant about making a Grand Slam final for the first time since a burglar sliced her racket hand in a terrifying attack in late 2016 at her home in the Czech Republic.

"It's probably a bit more special because of everything I've been through," said Kvitova, who feared she would never rejoin the game's elite after suffering permanent nerve damage.

But to make her comeback complete, the eighth seed needs to overcome U.S. Open champion Osaka, one of the few players who can match Kvitova's powerful serve and blazing groundstrokes.

The Czech said she must start strongly against the 21-year-old, whose meek off-court demeanor belies a ferocious competitive instinct.

"Naomi is on fire. She's in very good form," Kvitova said. "She's an aggressive player, which I am, as well. So I think it will be about who's going to take the first point and push the other a little bit."

Osaka has battled through three-setters three times on her way to the final and said advancing at Grand Slam level was sometimes more about the ability to outlast an opponent than outthink them.

"I'm playing the best players in the world, and I've been playing three sets most of the time," she said. "It's more like a battle of wills at this point."

The pair have never met and Osaka said she would have to adjust her game against the lanky left-hander.

Kvitova's coach Jiri Vanek said both finalists played in a similar manner.

"Osaka goes for winners, Petra goes for winners. You don't have time to come up with great tactics" he said. "Both of them play so fast, I think it's going to be about who has the bigger heart."

The final of this year's season-opening Grand Slam will also determine the world number one ranking after Romania's Simona Halep was bundled out in the fourth round.

Neither Osaka nor Kvitova has held the top spot before.

Osaka is currently sitting on a career-high ranking of four, while Kvitova even in her pomp only reached number two in 2011, the year she claimed her maiden major at Wimbledon.

The Czech, whose previous best at Melbourne Park was a final four appearance in 2012, said claiming the top spot would be "a very nice bonus" but she was only thinking about lifting the trophy.

Osaka was more enthusiastic about the prospect of becoming world number one but also said the title was her priority.

"Of course that's a very big deal for me," she said. "It's one of the biggest goals that I had when I heard it was possible after playing the quarters.

"But my main goal is winning this tournament. The ranking comes after that. I tend to do better if I focus on one goal."

Winning back-to-back Grand Slams would be a huge statement for Osaka, showing her success at Flushing Meadows was not a one-off.

She would be the first player other than American 23-time major winner Serena Williams to claim back-to-back majors since Kim Clijsters took the 2010 U.S. Open and 2011 Australian Open.

Osaka would also become the youngest to achieve the feat since Martina Hingis won the 1998 Australian Open after claiming the U.S. Open in 1997.

So close to victory, Naomi Osaka suddenly was letting the Australian Open final slip away. Three championship points? Gone. A sizable lead? Soon all gone, too.

She was playing poorly. She yelled at herself. Slammed a ball. Tugged at her visor's pink brim. Trudged to the locker room between sets with a towel draped over her head.

And then, after returning to the court, Osaka turned it all around just as quickly as she had dropped 23 of 27 points. Regrouping and reasserting herself, Osaka edged Petra Kvitova 7-6 (2), 5-7, 6-4 on Saturday night to win the Australian Open for a second consecutive Grand Slam title.

On top of that, Osaka will rise to No. 1 in the rankings.

Novak Djokovic strengthened his grip at the top of the men's ATP tennis ranking Monday following his destruction of Rafael Nadal in the Australian Open final. An outclassed Nadal, beaten in straight sets in just over two hours, held on to second spot in the rankings while Roger Federer slipped from third to six place.

Federer, the defending champion, was eliminated in the round of 16 by Greek giant-killer Stefanos Tsitsipas Alexander Zverev replaces Federer in third position ahead of Juan Martin Del Potro, fourth, who missed the Australian Open.

Despite his early elimination in Melbourne, South African Kevin Anderson, a Wimbledon finalist last year, moved up a spot into fifth.

Japan's Kei Nishikori, meanwhile, rises two places to seventh after reaching the quarterfinals in Melbourne. Tsitsipas, eliminated by Nadal in the semifinals, jumped three places and is knocking on the door of the top 10 in 12th place.

Latest ATP ranking:

1. Novak Djokovic (SRB) 10,955 pts
2. Rafael Nadal (ESP) 8,320
3. Alexander Zverev (GER) 6,475 (+1)
4. Juan Martin Del Potro (ARG) 5,060 (+1)
5. Kevin Anderson (RSA) 4,845 (+1)
6. Roger Federer (SUI) 4,600 (-3)
7. Kei Nishikori (JPN) 4,110 (+2)
8. Dominic Thiem (AUT) 3,960
9. John Isner (USA) 3,155 (+1)
10. Marin Cilic (CRO) 3,140 (-3)

Women's rankings

Naomi Osaka, winner of the Australian Open, has jumped to the top of women's tennis with her beaten opponent Petra Kvitova rising to second in Monday's WTA rankings. Osaka climbed three places after beating the Czech in Melbourne on Saturday. Kvitova moved up four places.

The 21-year-old Japanese player has only won three career titles, but those include the last two majors, after she won the U.S. Open in September.

Romanian former number one Simona Halep, knocked out by Serena Williams in the round of 16 in Melbourne, fell two spots to third. Dane Caroline Wozniacki, whose defense of her Australian Open title ended in the third round, fell six places to ninth.

The biggest rise of the week was by the 25-year-old American Danielle Collins who leaped 12 places to 23rd after her run to the semi-finals.

The other semifinalist, Czech Karolina Pliskova, who saved four match points against Williams in their quarterfinal, also advanced, gaining three places to fifth in the world.

Williams, who fell to 491 after her maternity break last year, continued her rise, gaining five places to 11th.

WTA rankings:

1. Naomi Osaka (JPN) 7,030 pts (+3)
2. Petra Kvitova (CZE) 6,290 (+4)
3. Simona Halep (ROM) 5,582 (-2)
4. Sloane Stephens (USA) 5,307 (+1)
5. Karolina Pliskova (CZE) 5,100 (+3)
6. Angelique Kerber (GER) 4,965 (-4)
7. Elina Svitolina (UKR) 4,940
8. Kiki Bertens (NED) 4,430 (+1)
9. Caroline Wozniacki (DEN) 3,566 (-6)
10. Aryna Sabalenka (BLR) 3,485 (+1)