By Sudipto Ganguly
MELBOURNE (Reuters) - Big-serving Milos Raonic eased into the Australian Open quarter-finals with a surprisingly one-sided 6-1 6-1 7-6(5) victory over frustrated fourth seed Alexander Zverev, who smashed his racket to a pulp as Monday's match was slipping away.
The 21-year-old German, who won the 2018 ATP Finals but has struggled at the Grand Slams, was broken six times in the first two sets before the Canadian converted his fourth match point in a tight third set to seal the contest in less than two hours.
After serving his fifth double-fault to cough up a second break in the second set, Zverev lost his temper and hammered his racquet into the ground until it was mangled, earning him a code violation warning from the umpire.
The 28-year-old Raonic will face either Croatian 11th seed Borna Coric or Frenchman Lucas Pouille, who is seeded 28th, for a place in the semi-finals.
(Reporting by Sudipto Ganguly; Editing by John O'Brien)