Frances Tiafoe’s grand slam coming of age has continued at the Australian Open, with the unseeded American celebrating his 21st birthday in style with an emotional four-set quarter-final win over Grigor Dimitrov.

Tiafoe arrived at Melbourne Park with an unflattering 5-11 career win-loss record at the majors.

But after dispatching 2017 Open semi-finalist Dimitrov 7-5 7-6 (8-6) 6-7 (1-7) 7-5 on Sunday, he has now advanced all the way to a likely quarter-final showdown with 17-times major winner Rafael Nadal.