MELBOURNE, Jan 27 - Alexander Zverev will go into the Australian Open semi-finals relishing being injury-free for the first time in a year as he continues his quest for a first Grand Slam title having seen off Learner Tien in Tuesday's quarter-finals.

The German third seed, who lost last year's final to Jannik Sinner, beat the 20-year-old American 6-3 6-7(5) 6-1 7-6(3) to set up a last-four meeting with either Carlos Alcaraz or Alex de Minaur.