Miami: Zverev battles past Kyrgios; Stephens, Azarenka advance to face off in semis

IMAGES from the Miami Masters played in Key Biscayne, Florida on Tuesday

Alexander Zverev capitalised on a fast start against Australian Nick Kyrgios to grind out a 6-4, 6-4 victory in a battle between two of the sport's brightest prospects to advance to the quarter-finals of the Miami Open on Tuesday.

The 20-year-old German is looking to win the third Masters event of his career and advanced to a last-eight showdown against Croatia's Borna Coric, who ended the run of Canadian prospect Denis Shapovalov 7-6(2), 4-6, 6-4 in a tight encounter.

The fourth-seeded Zverev had battled through a pair of three-set wins in his opening two rounds but was keen to make short work of Kyrgios when he broke serve in the first game and stormed to a 5-1 advantage.

The 22-year-old Kyrgios battled back to win three straight games to make it 5-4 but Zverev held his nerve and serve to close out the opener in 34 minutes.

Kyrgios, who had reached the Miami semi-finals in the previous two years, saw his hopes of at least matching that feat evaporate in the second set after his opponent secured the only break in the fifth game and rode it out for a well-earned win.

Earlier, big-serving American John Isner overcame second-seeded Croatian Marin Cilic 7-6(0), 6-3 to advance to the quarter-finals, where he will face South Korean Chung Hyeon, who dominated Joao Sousa in a routine 6-4, 6-3 win.

Also advancing was Juan Martin del Potro of Argentina, who defeated Filip Krajinovic 6-4, 6-2 for his 14th consecutive victory as the fifth seed looks to back up his Indian Wells title triumph with another tournament win.

"I will try to keep going and see how far I can go," said Del Potro, who next meets big-serving Milos Raonic after the Canadian cruised to a 6-3, 6-4 victory against an overpowered Jeremy Chardy of France.

Del Potro beat Raonic in last week's semi-finals in California before edging out Federer in the title match.

"It'll be a difficult match," Raonic admitted.

"He's been the best player in the world for the past four, five weeks." Elsewhere, Spaniard Pablo Carreno Busta crushed compatriot Fernando Verdasco 6-0, 6-3 to reach the second Masters 1000 quarter-final of his career.

He will face South Africa's Kevin Anderson, who used his big serve to full effect in a 7-6(3), 6-4 win over 20-year-old American Frances Tiafoe.

American Sloane Stephens needed just over an hour to cruise past Germany's former world number one Angelique Kerber 6-1, 6-2 and reach the Miami Open semi-finals for her first time on Tuesday.

The US Open champion fired her 22nd winner on match point to dispatch the 10th-seeded Kerber and set up a showdown with three-time champion Victoria Azarenka, who scored a 7-5, 6-3 victory over world number six Karolina Pliskova.

The win guarantees that 25-year-old Florida native Stephens will make her debut in the top 10 when the WTA rankings are released after the tournament.

Tuesday's win was Stephens's second straight triumph over a former world number one after she defeated third-seeded Garbine Muguruza to reach the quarter-finals on Monday.

Stephens said staying consistent was the key to her win over Kerber.

“When you play a player like Angie you have to execute your game well,” Stephens told reporters.

“And then you have to make sure that when you are executing your game you stick with it.

Like a lot of times you can venture off and start, you know, doing other things.”

Stephens faced just one break point in reaching her first semi-final since winning the U.S. Open last year.

Kerber, who was playing less than 24 hours after a three-set win over qualifier Wang Yafan that lasted nearly three hours, said her schedule was beginning to take its toll.

“I was really feeling a little bit tired today," Kerber said.

“I mean, of course it was windy, it was tricky, but I have played so many matches in the last three months that I was feeling it a little bit today in my body."

Azarenka continued her strong run in Miami where she has now won 11 straight dating back to her 2016 title triumph.

Azarenka, who broke Pliskova seven times, will be playing in her first semi-final in two years. The former world number one was absent from the game for eight months due to a custody dispute involving her son.