Miami Open Masters 2018 Results: Scores, Bracket and Schedule After Tuesday

A couple of Americans shined at the 2018 Miami Open in Key Biscayne, Florida, on Tuesday.

John Isner looked as sharp as he has in months with a straight-set win over Marin Cilic on the men's side, while 2017 U.S. Open champion Sloane Stephens cruised by Angelique Kerber and booked a spot in the semifinals on the women's side.

Below, you'll find a rundown of the men's fourth-round and women's quarterfinal results, as well as a recap of the day's top matches and a quick glimpse at Wednesday's order of play.

Tuesday's Results

Men's 4th-Round Scores

• No. 4 Alexander Zverev def. No. 17 Nick Kyrgios: 6-4, 6-4
• No. 5 Juan Martin del Potro def. No. 22 Filip Krajinovic: 6-4, 6-2
• No. 6 Kevin Anderson def. Frances Tiafoe: 7-6 (3), 6-4
• No. 14 John Isner def. No. 2 Marin Cilic: 7-6 (0), 6-3
• No. 16 Pablo Carreno Busta def. No. 31 Fernando Verdasco: 6-0, 6-3
• No. 19 Hyeon Chung def. Joao Sousa: 6-4, 6-3
• No. 20 Milos Raonic def. Jeremy Chardy: 6-3, 6-4
• No. 29 Borna Coric def. Denis Shapovalov: 7-6 (2), 4-6, 6-4

Women's Quarterfinal Scores

• No. 13 Sloane Stephens def. No. 10 Angelique Kerber: 6-1, 6-2
• Victoria Azarenka def. No. 5 Karolina Pliskova: 7-5, 6-3

Updated draws available at MiamiOpen.com.

Men's Recap

Lynne Sladky/Associated Press

Put simply, Isner has been in a funk all season.

He bowed out of the Australian Open in the first round, lost his first match at the ATP New York Open and parted the proceedings in Indian Wells following a second-round loss to Gael Monfils.

However, the American finally seems to be finding his footing in South Florida.

Fresh off a third-round win over Mikhail Youzhny, Isner produced his finest effort of the season and throttled No. 2 Marin Cilic, 7-6 (0), 6-3, behind 12 aces and wins on 41 of his 48 first-serve points.

"I was very happy with how I played, especially with how I served," Isner said after the match, according to the ATP. "That's certainly the best I've served all year. ... Today I served exceptionally well and that's what, of course, kept me in the match and put scoreboard pressure on him and I finally was able to break through and get a break."

With his confidence skyrocketing, Isner will now head for a quarterfinal clash with Hyeon Chung—who defeated Joao Sousa in straight sets on Tuesday.

Isner is 2-1 lifetime versus Chung, but he lost the last meeting at the start of the year in New Zealand.

"It's going to be tough," Isner said. "... He's found the magic potion this year for sure. He's playing incredibly well. It's going to be a very tough match."

One of the other highlights in men's action was the continued dominance of Juan Martin del Potro.

The Argentine, who at one point trailed 4-1 in the first set, bounced back and won five straight games in the opening frame before squashing Filip Krajinovic in the second set.

Del Potro will set his sights on a 15th straight win in the quarterfinals against Milos Raonic after the Canadian dispatched Jeremy Chardy in Round 4.

Those two have split their all-time series two matches apiece. Del Potro won the last tilt, 6-2, 6-3, in the semifinals at Indian Wells.

Women's Recap

Like Isner, Stephens struggled with consistency entering the Miami Open.

That all appears to be changing now.

Not only did the 25-year-old beat Garbine Muguruza in the fourth round, but she breezed past No. 10 Kerber, 6-1, 6-2, on Tuesday to lock up a spot in the semifinals behind 22 winners, as Tennis Channel documented:

According to TennisNow, Stephens has owned Kerber of late:

Thanks to her triumphant performance, Stephens is headed for her first-ever top-10 ranking on the WTA circuit.

"It's awesome. Obviously something I have wanted to do for a while, and...it's really not easy," she said, per WTA.com's Alex Macpherson. "Getting to No. 11 was hard, and so getting into the top 10 is pretty special. I'm super excited about that."

Elsewhere, Victoria Azarenka took care of Karolina Pliskova in straight sets to set up a semifinal date with Stephens.

On paper, that's a favorable matchup for Azarenka. She's 3-1 lifetime against Stephens, and all three wins came on the Grand Slam stage at the Australian Open.

That said, Stephens' lone win came earlier this month when she downed Azarenka, 6-1, 7-5, in Indian Wells.

Order of Play: Wednesday, March 28

Stadium

No. 6 Jelena Ostapenko vs. No. 4 Elina Svitolina (1 p.m. ET)

No. 19 Hyeon Chung vs. No. 14 John Isner (Not before 3 p.m. ET)

No. 8 Venus Williams vs. Danielle Collins (7 p.m. ET)

No. 5 Juan Martin del Potro vs. No. 20 Milos Raonic (Not before 9 p.m. ET)