Stefanos Tsitsipas is through to the third round and closer to a potential meeting with defending champion Roger Federer at Melbourne Park.
The Greek 20-year-old beat Viktor Troicki 6-3, 2-6, 6-2, 7-5 but wasted a lot of break-point opportunities as the Serbian player saved 15 of 19 chances created by Tsitsipas.
Considered one of the new breed of young talented players on the ATP Tour, Tsitsipas won at Stockholm last year and was a finalist in two other tournaments.
He will next play 19th-seeded Nikoloz Basilashvili, who beat Stefano Travaglie 6-3, 3-6, 6-3, 4-6, 6-3, also on Wednesday. Tsitsipas could play Federer in the fourth round.