Grigor Dimitrov overcame a huge scare to reach the Australian Open fourth round as Tomas Berdych eased through on Friday.
Dimitrov needed three hours 28 minutes in Melbourne's heat to edge 2006 runner-up Marcos Baghdatis 4-6 6-3 3-6 6-3 6-3.
The Bulgarian 10th seed had won five of his previous six matches against Baghdatis but needed to produce some of his best in their third-round clash.
Dimitrov, considered a chance of winning his maiden grand slam in Australia, hit 42 winners in his victory.
Baghdatis often saves his best for the Australian Open but he dropped serve in the third game of the fifth set and was unable to recover.
The Cypriot hit 51 winners and was well supported, as he always is in Melbourne, on Show Court Three.
But Dimitrov's class eventually got him over the line.
It was a different story on Margaret Court Arena, where Berdych hit 20 aces to beat Serbian Viktor Troicki 6-4 6-3 6-4.
The Czech seventh seed was impressive, finishing with 55 winners in the convincing victory.