Marc Polmans has held his nerve to claim the biggest victory of his career, beating Kazakhstan’s Mikhail Kukushkin in five sets in the opening round of the Australian Open.

Polmans was broken when serving for the match at 5-4 in the fourth set and then blew three match points in the ensuing tiebreak.

But the 22-year-old Australian regrouped to win 6-4 6-3 4-6 6-7 (8-10) 6-4 in a marathon encounter lasting four hours and 17 minutes, setting up a second-round clash with Serbian No.24 seed Dusan Lajovic.