The 2024 Miami Open champion Sinner had faced the toughest match of his tournament so far in the fourth round, with the Italian pushed hard in a 7-5, 7-6(4) victory over Alex Michelsen on Tuesday.
However, the 24-year-old faced little trouble against 19th seed Tiafoe in the last eight, dropping just four games in a dominant 6-2, 6-2 win over the American.
It took just 71 minutes for Sinner to claim the most dominant win of his Miami Open campaign so far, with the Italian not facing a single break point on his own serve, while breaking Tiafoe on four separate occasions.
“I feel like starting the match is very important. When you start with a break up it gives you slightly good confidence,” said Sinner, speaking to Tennis TV after his win.
“At the same time, they might be very aggressive. I try to stay as compact as possible with my shots, also mentally. There can be some ups and downs from both sides.
“I try to be very calm, taking the chances I can get. I think today that was the key.”
Earlier in the tournament, Sinner broke Novak Djokovic’s previous record of 24 consecutive sets won at Masters 1000 events.
Victory over Tiafoe on Thursday has extended the Italian’s new record to 30 sets in a row at Masters events, having previously won the Paris Masters last November and Indian Wells earlier this month without dropping a single set.
However, that is not the only milestone that Sinner has now hit at the Miami Open this year.
Since the Miami Open was held in 1985, the Italian is the first man to reach the semi-final four times in his first five appearances at the tournament.
Sinner retired injured in his quarter-final in 2022, though he was the champion in 2024, and the runner-up in both 2021 and 2023; he did not contest the event in 2025 due to his three-month doping suspension.
And, since the first edition of the Miami Open 41 years ago, the four-time Grand Slam champion is the first man to win 14 straight matches across the ‘Sunshine Double’ without dropping a set.
This year, Sinner has won six matches in Indian Wells and four matches — and counting — in Miami without losing a set, while he won the final four matches of his 2024 Miami Open title run in straight sets.
He will hope to continue his stellar run going into his semi-final on Friday, where he will faces third seed Alexander Zverev, who was utterly dominant in his 6-1, 6-2 win over Francisco Cerundolo.
Should Sinner lift the title in Miami this year, he would become the first man since Roger Federer in 2017 to achieve the Sunshine Double.
