23:57 CET - On the other side of the draw, Tommy Paul has moved into the last eight by comfortably beating Tomas Martin Etcheverry.
His fellow Americans Frances Tiafoe and Coco Gauff will now both look to get wins of their own, with Belinda Bencic standing between the latter and a place in the semis.
23:48 CET - Sinner has secured his spot in the quarter-finals by winning what turned into an absolute thriller!
Michelsen continued to play excellently in the second set and roared into a 5-2 lead, but the Italian then bounced back to take it into a tiebreak, where he again came from behind, overturning a 3-1 deficit to win it 7-4.
The two both played top tennis and contested some epic rallies, and Sinner ultimately stood firm to win a record-extending 28th set in a row in Masters 1000 tournaments and seal his ninth consecutive victory.
22:55 CET - Jannik Sinner is a set to the good against Alex Michelsen, but getting that lead was far from easy, with the American more than holding his own. He led for most of the opener before finally being broken at 5-5.
Can he continue to cause the Italian problems? Follow the clash here.
21:47 CET - Just as she did in the Doha final last month, Muchova has won two gruelling sets to battle past Mboko, claiming victory after one hour and 48 minutes.
It was a match of fine margins, with both players serving excellently and facing just two break points, but the Czech player was able to save both of hers and that made the difference.
With a 7-5, 7-6 win, she becomes the first semi-finalist of the year.
21:22 CET - Arthur Fils' excellent start to 2026 has continued, with the young Frenchman moving into the quarter-finals with a 6-4, 6-7, 6-4 win over Valentin Vacherot.
The 21-year-old, who made the final in Doha last month, has now made the last eight of a Masters 1000 tournament five times and has done so twice in Miami. With injury issues behind me, he's starting to look like one of the biggest talents around again.
19:39 CET - Another big name has been dumped out of the men's tournament in Florida, with sixth seed Taylor Fritz falling in three sets to Jiri Lehecka, 6-4, 6-7(4), 6-2.
The American, who has struggled for consistency in the past 12 months, committed 31 unforced errors throughout the contest, while failing to convert any of his five break-point opportunities.
Up next for 21st seed Lehecka is a quarter-final meeting with surprise package Martin Landaluce.
18:45 CET - Talented Spaniard Martin Landaluce has continued his incredible breakthrough run in Miami, with the world number 151 sealing a quarter-final berth after coming from match point down to outlast Sebastian Korda 2-6, 7-6(6), 6-4.
Having claimed the scalp of top seed Carlos Alcaraz in the previous round, Korda was unable to back up that triumph, as his 20-year-old opponent produced some excellent tennis in the key moments, winning 77% of points behind his first serve.
Landaluce, who won two matches in qualifying just to make the full draw, will now face the winner of Taylor Fritz vs Jiri Lehecka for a place in the semi-finals.
15:58 CET - Play is about to get underway in Florida, with Carlos Alcaraz's conqueror, Sebastian Korda, taking on Spanish talent Martin Landaluce for a spot in the quarter-finals.
Keep track of that match right here.
14:00 CET - Good afternoon and welcome to our coverage of today's action in Miami, as the women's quarter-finals get underway and all eight men's last-16 matches take place.
The first quarter-final clash of the day sees rising star Victoria Mboko take on Karolina Muchova at 19:00 CET, in what is a repeat of the Doha final back in February, which the Czech won in two hard-fought sets.
Following that match, fourth seed Coco Gauff comes up against Belinda Bencic at 00:00 CET, with the Swiss player looking in great form after a straight-set victory over Amanda Anisimova in the previous round.
Meanwhile, on the men's side of the tournament, play gets underway in a couple of hours at 16:00 CET, with Taylor Fritz and Arthur Fils continuing their campaigns against Jiri Lehecka and Valentin Vacherot, respectively.
Later on, 2024 champion and heavy favourite for the title, Jannik Sinner, faces Alex Michelsen at 21:00 CET, while third seed Alexander Zverev takes on Quentin Halys in the final match of the day at 01:30 CET.
Check out the full men's and women's schedules via the links.