3. Dimitrov, Nadal advance

Nadal, Dimitrov survive rigorous four-set matches.

Grigor Dimitrov and Rafael Nadal (above) earned quarterfinal spots at the Australian Open on Sunday. Six-time winner Novak Djokovic, defending champ Roger Federer and 2016 champion Angelique Kerber look to join them today.

MELBOURNE, AUSTRALIA — U.S. Open finalist Madison Keys advanced to the Australian Open quarterfinals with a 6-3, 6-2 victory over eighth-seeded Caroline Garcia of France early today.

Keys, the 17th seed, is the only American woman left in the draw. The remaining American man, Tennys Sandgren, was to play Dominic Thiem later in the day.

Keys, 22, didn’t play at Melbourne Park last year because of wrist surgery, but she made her first big splash at a Grand Slam event when she reached the Australian semifinals in 2015. She went on to make the Wimbledon quarterfinals that year but didn’t have a better result until she lost to fellow American Sloane Stephens in the U.S. Open final last September.

In the quarterfinals, Keys will play the winner of the match between 2016 Australian champion Angelique Kerber and Hsieh Su-wei.

On the men’s side, top seed Rafael Nadal and third seed Grigor Dimitrov reached the quarterfinals with tough victories Sunday night.

Nadal secured his spot in a 10th Australian Open quarterfinal, beating Diego Schwartzman 6-3, 6-7 (4),

6-3, 6-3 in 3 hours and 51 minutes.

Nadal, a 16-time major winner, draped an arm around his Argentine friend and patted him on top of the head at the net afterward. If he needed a fitness test in the first week in his comeback from an injured right knee, he got it.

“It was a good test for me. It was a lot of hours on court. Moments under pressure,” Nadal said.

Nadal will next play 2014 U.S. Open champion Marin Cilic, the sixth seed. He collected his 100th Grand Slam match win with a 6-7 (2), 6-3, 7-6 (0), 7-6 (3) victory over No. 10 Pablo Carreno Busta.

Dimitrov outlasted Australian Nick Kyrgios 7-6 (3), 7-6

(4), 4-6, 7-6 (4) even though Kyrgios managed one more break of serve than Dimitrov, 3-2, and had 36 aces.

Kyrgios said Dimitrov is a threat to win his first Grand Slam title.

“He hasn’t even found his best form yet and he’s still getting through all those matches, which is pretty frightening,” Kyrgios said. “Once he finds his feet and he has more confidence, he’s got a real chance at winning it.”

Dimitrov will next play Britain’s Kyle Edmund, who reached his first Grand Slam quarterfinal with a 6-7 (4), 7-5, 6-2, 6-3 victory over Andreas Seppi. Edmund rallied from a set and a break down, winning with 25 aces.

ANDY BROWNBILL / ASSOCIATED PRESS Madison Keys serves during her fourth-round victory over Caroline Garcia. Keys, the U.S. Open runner-up, reached the Australian Open quarterfinals for the second time in four years.