Gold Coaster Bernard Tomic has survived a battle against Fernando Verdasco to move into the second round of the Australian Open.

The 19-year-old fought back from two sets down to beat the World No. 22 4-6 6-7 6-4 6-2 7-5 in a four-hour marathon.

Tomic credited the Melbourne Park crowd with getting him back on track.

He told Channel Seven, he didn't know what happened to force the turn around: "The first set was very tough. I didn't feel 100 per cent. I don't know how I found the energy to lift."

He then turned to the crowd saying, "it was you ... it wasn't me."

The 19-year-old faces American Sam Querrey in the second round on Wednesday.