Jannik Sinner defeated Alex Michelsen to reach the Miami Open quarter-finals, keeping his Sunshine Double hopes intact. He bided his time completing a 7-5, 7-6 (7/4) win in 1hr 41min. The four-time Grand Slam champion, who will face 19th seed Frances Tiafoe in the last eight, was made to work hard by the 40th-ranked Michelsen.