The 30-year-old upset American John Isner 6-4 3-6 6-3 6-3 on Margaret Court Arena in day one of the 2018 Australian Open.

The world No.78 will now meet Alexandr Dolgopolov in his third attempt to prevail to the third round of the Open.

But he said he was accustomed to playing the big guns in world tennis.

“No, I'm not surprised at all (of the win),” Ebden said after the upset.

“I don't know how to say, I expect to win. I know if I execute and do the things that I was trying to do, I would give myself a good shot at winning. It was probably the same as John was thinking.

“It's the same with all the guys. I'm getting used to now playing always top, top level of myself and against these guys who can play the same level. Winning against them often now, losing sometimes, but still being just about there winning those matches also.

“I know the level that I can play and maintain now consistently. I've got to keep working every day basically on all the little things to make that happen. It doesn't just happen by itself.

“I can't lapse even for more than maybe a day off here or there. I’ve got to keep things rolling at a very high level to maintain that.”

Dolgopolov is currently ranked 37 in the world and will play Ebden for the first time.

“I'm very aware of him, practiced a lot together and I know he can play at a good level,” he said.

“He’s won tournaments, been in finals. Been top 20 at least, nearly top 10.

“On the flipside, when he doesn't do things that great, he doesn't play that level. It's going to be, well, a different sort of match, but the same thing. Another player, another match.”