Jannik Sinner advances to Miami Open quarterfinals

Italian Jannik Sinner, ranked second in the world, continued his quest for a "solar double" by reaching the quarterfinals of the Miami Masters 1000 tournament with a hard-fought 7-5, 7-6 (7-4) victory over American Alex Michelsen.

Sinner, aiming to win the Miami title after his victory at Indian Wells the previous Sunday, needed one hour and 41 minutes to overcome Mikkelsen. 

Straight sets

The four-time Grand Slam champion faced stiff resistance from world number 40 Michelsen, who leveled the score at 5-5 until the tenth game before Sinner lost his serve in the eleventh game to trail 5-6. Sinner then lost the set 5-7 after 46 minutes.

Mikkelsen continued his resilience in the second set, breaking Sinner's serve in the sixth game to take a 4-2 lead, then extending it to 5-2. However, the Italian responded in the ninth game, winning three consecutive games to level the score at 5-5 and then 6-6, forcing a tiebreak which he won 7-4 to take the set in 55 minutes.

"I feel I served well at crucial moments, and that helped me, especially in the difficult times," Sinner said.

Sinner hit 15 aces compared to just three for Michelsen.

"But the match wasn't easy today. I played last night, and now it's daytime, so the conditions were completely different," he added.

Sinner will next face another American, Frances Tiafoe, who defeated Frenchman Terence Atman 6-4, 1-6, 6-4.