Jannik Sinner has no issues at Australian Open as Stefanos Tsitsipas crashes out

“It was a difficult first-round match,” said Tsitsipas. “I knew I was dealing with a pretty serious opponent because I’ve played him before and I have lost."

SAINTS AND SINNER: Defending champion Jannik Sinner moved into round two (Asanka Brendon Ratnayake/AP)

Defending champion Jannik Sinner extended his winning run at the Australian Open but young American Alex Michelsen caused the first big upset by knocking out former finalist Stefanos Tsitsipas in the opening round.

Tsitsipas was beaten by Novak Djokovic in the final two years ago and is also a three-time semi-finalist, but he has struggled since reaching the quarter-finals of the French Open last spring.