Juan Martin del Potro made his devoted fans home happy by powering into the ATP Miami Open quarter-finals with a 6-4, 6-2 triumph over Serbian Filip Krajinovic.
Roared on by a partisan crowd, the 29-year-old Argentinian recovered from 1-4 down in the first set to reel off nine games in a row on his way to a last-eight match with Canada’s Milos Raonic.
Del Potro’s welcome return to form and fitness saw him win the Indian Wells title and continue to impress at the last tournament in Key Biscayne before a move north to the NFL Miami Dolphins’ home stadium next year.
“Playing here they make it special for the South American players and I am trying to enjoy the last time playing in Key Biscayne,” Del Potro said. “I know many Argentine fans live here and are so close. I will miss them.”
Windy conditions hampered players all day and the former US Open champion took time to find his groove in his first meeting with 27th-ranked Krajinovic.
“The weather was so bad to play tennis. We couldn’t feel the ball 100%. We couldn’t hit from the baseline,” Del Potro admitted. I’m confident I will feel better tomorrow. The better weather will make me feel better on court.”
Raonic, who easily saw off Frenchman Jeremy Chardy 6-3 6-4, lost to del Potro in the Indian Wells semi-finals and will be eagerly seeking revenge.
“It will be a different match to the one we played in Indian Wells, different conditions,” Del Potro said. “Milos is improving and playing very solid. He has the potential to win the tournament. It will be a good match to test my fitness and see what level I’m at.
“I don’t feel pressure. I am just going down my own road and seeing how far I can get. I am not thinking about ranking or anything. Just the last time here in Key Biscayne.”Del Potro is the top seed remaining after second seed Marin Cilic was beaten 7-6 (7/0), 6-3 by American John Isner.
The Croatian’s run was halted by big-serving Isner in just 87 minutes to set up a last-eight meeting with South Korean 19th seed Chung Hyeon.
It was a fine performance by Isner, the 14th seed, who rattled down 12 aces and was boosted by winning 85 % of points on his first serve.
All three of Isner’s wins over the 2014 US Open champion have now come in ATP Masters events and once a first set tie-break was negotiated in windswept conditions, the 32 year-old confidently held his nerve to send Cilic home.
Isner has never won an ATP Masters event but this display has fuelled hopes this could be his time.
“I think in these events, the format is very good for me: two-out-of-three sets,” Isner said.
“In a situation like that, if I’m feeling fit and healthy, which I am, and serving like I did today, I can beat a lot of people playing like that.” In the late match, impressive Alexander Zverev, the fourth seed, powered past an out-of-sorts Nick Kyrgios 6-4 6-4 to set up a meeting with Croatian Borna Coric in the last eight.
Australian firebrand Kyrgios has been struggling with an elbow injury and Zverev’s power and precision was simply too hot to handle as the German reached the quarter-finals for the second year in succession.

Stephens, Azarenka face off in Miami semis
 Miami: 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’ 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 US 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.