Thanasi Kokkinakis is through to the quarter-finals at the Sydney Pro Tour after defeated Philip Sekulic 6-2, 7(7)-6(4).

It was another strong performance by Kokkinakis, especially with his serve game, much like in his prior match against Christian Langmo.

He hit 15 aces and had a 77 per cent win rate on his first serve, and won three of the 14 break points he had on his fellow Aussie.

The second seed next faces Japan’s Hikaru Shiraishi tomorrow (AEDT) to book a spot in the final four.