Australian teenager Thanasi Kokkinakis has qualified for the main draw of the Istanbul Open to close in on the top 100.

Kokkinakis, who is currently ranked a career-high No.103, advanced when his Italian opponent Lorenzo Giustino retired in the qualifying tournament citing nausea when trailing 6-0 1-0.

The 19-year-old South Australian is in solid form, defeating two opponents in straight sets to reach the final round of the qualifying event.

It is the fourth ATP main draw Kokkinakis has qualified for this year, and takes his season win-loss record to 18-7.

He will line up against Serb Dusan Lajovic in the first round of the main draw on Tuesday.

The clay court Istanbul Open is the first ATP World Tour event to be held in Turkey, and is headlined by top seed and world No.2 Roger Federer.