Italy's world number two Jannik Sinner overcame a stiff challenge from American Alex Michelsen to prevail 7-5, 7-6 on Tuesday night and progress to the quarter-finals of the Miami Open.     In doing so, the 24-year-old also extended his record for the number of consecutive sets won at the Masters 1000 level, 28, after surpassing Novak Djokovic's previous record of 24 in the last round.     But he had to work hard for it, coming back from a break down when Michelsen was serving for the second

Tag-uri: Italia