Sebastian Korda knocked off Alcaraz in Miami. Can Alex Michelsen shock Sinner?

Before each day's play at the Miami Open, we'll preview and predict three must-see matches—stream them all on the Tennis Channel app.

Karolina Muchova vs. Victoria Mboko

“I just know it’s going to be very tough,” Mboko says of facing Muchova.

She knows that from recent experience, having lost to the Czech last month in the Doha final, 6-4, 7-5. And Mboko might also be guessing it from the scores of Muchova’s last match, a 6-0, 6-2 dismantling of Alex Eala on Monday.

But there are reasons to think Mboko will be just as tough for Muchova to face. She’s ranked five spots higher than her (No. 9 to 14). She went a round farther than her at Indian Wells, losing in two tight sets to Aryna Sabalenka in the quarterfinals. And she just beat a fellow Top 10 player, Mirra Andreeva, in three sets.

In Doha, Muchova had more resources she could tap than Mboko. She had her slice backhand, she had her touch, she had her volley, she had her underrated serve. Mboko, for now, relies on the pace of her ground strokes and the speed of her feet. Her goal for this match, it sounds like, is to get more out of her serve, and get on top of the rallies earlier.

“Hopefully I can kind of just work with my game and just see what patterns I could do, or whatever I can do to try to gain more free points,” Mboko says.

Muchova can be overpowered; we saw Iga Swiatek beat her 6-2, 6-0 two weeks ago in Indian Wells. And Mboko is a quick study; at the start of the year, she lost 3 and 1 to Andreeva. I’ll say that beating Andreeva on Monday will do more for her match toughness than rolling over Eala will do for Muchova’s. Winner: Mboko

Jannik Sinner vs. Alex Michelsen

On Sunday, Sebastian Korda of the U.S. put his recent good form to the ultimate test: a match with Carlos Alcaraz. Korda, as you know, passed that test. Aced it, in fact.

On Tuesday, his countryman Michelsen will try to follow his lead when he faces the other ultimate test in men’s tennis: A match with Sinner.

After treading water for a lot of 2025, the 21-year-old Californian has shown signs of maturation of late. He started the year with a semifinal run in Brisbane, and he won three matches in Indian Wells, including one over Taylor Fritz. In Miami, he has survived his last two matches, against Norrie and Tabilo, 6-4 in the third.

Now comes the reality check. Michelsen has faced Sinner twice, and lost both times. But their first meeting, in Cincinnati in 2024, was closer than the 6-4, 7-5 score might indicate. That day a 19-year-old Michelsen proved capable of going shot for shot with Sinner for long stretches, before succumbing to the moment at the end of each set. A month later at the US Open it wasn’t so close; Sinner lost just six games in three sets.

In 2026, Sinner may be an even better player, and he clearly likes the courts and conditions in Miami, where he’s a three-time finalist. So far this year, though, he has faced two undersized opponents in Damir Dzumhur and Corentin Moutet. The 6’4” Michelsen will bring a lot more heat, especially on his serve, than those guys.

Sinner’s the favorite, but it feels like Michelsen is in the process of setting down and learning to make the most of his once-raw talents. With the right crowd in his corner, it could be interesting. Winner: Sinner

Coco Gauff vs. Belinda Bencic

“There’s always that extra layer,” Gauff says of playing in South Florida, where she grew up and still lives. “You just see familiar faces in the crowd. You don’t want to disappoint them.”

That “extra layer” hasn’t helped her here in the past. This is her seventh appearance in Miami, and her first quarterfinal. It wasn’t easy getting here, either. She has won all three of her matches, against unseeded opponents, in three sets.

In that sense, it has been a classic Coco run. She has missed serves and forehands, dropped sets, and looked lost for stretches; but she has found ways to lengthen points, use her legs, and scrap her way to wins.

Can she make that work against a higher-caliber player like Bencic?

The American and the Swiss played four times in 2025, and Gauff won three of them. But each was competitive. Two of Gauff’s wins came in three sets, and Bencic closed out her lone victory, at Indian Wells, 6-4 in the third. Where Gauff likes to defend, Bencic likes to counter-punch, which means that neither woman can easily get the ball past the other. Put those two styles up against each other and you’re virtually guaranteed long points and many momentum swings.

Speaking of momentum, Bencic will be coming in with a lot of it. On Monday evening, she played an outstanding match, full of clean ball-striking, to dismiss sixth-ranked Amanda Anisimova 6-2, 6-2. If she can avoid a letdown 24 hours later, and ignore that “extra layer” of Guaff fans, she may be the favorite. Winner: Bencic