Reigning world champion Lewis Hamilton said it was a "shock" to twice break a track record as he took pole position for the Australian Grand Prix.

Hamilton took his sixth consecutive pole at Albert Park with teammate Valtteri Bottas completing a Mercedes lockout of the front row ahead of Sunday's season opener.

But the 34-year-old, gunning for his sixth world championship, is aware of the challenge posed by Ferrari who will be "pushing hard" with Sebastian Vettel eager to take his third consecutive win in Melbourne.

Mercedes were considered to be off the pace of the Italian constructor after winter testing in Barcelona, but Hamilton topped all three practice sessions going 0.264 seconds clear in Saturday's final practice.

In qualification, he set a new track record on one minute 21.014 seconds with a tidy lap in the second qualifying session, surpassing it in the top 10 shootout with a 1min 20.486secs, 0.704secs quicker than Vettel.

"Since practice from day one until the last day when we left and went back to the factory we knew we had work to do," he said.

"I felt good that we had a decent package to work with but we were aware we might be slightly behind.

"I really was not expecting to see the performance difference that we have here. It had been so close throughout the whole weekend between us all."

"I know that Ferrari are going to be pushing hard and progressing over the coming days and tomorrow I'm sure they will be putting up a good fight as they are always strong in the races."

Bottas held provisional pole with a flying lap of one minute 20.598 seconds, with Hamilton adding he needed to "pull something special out" to pip the Finn.

Vettel said the gap to the Mercedes duo did not quash thoughts of victory, adding: "The race is over when there's the chequered flag."

"Obviously Mercedes are the clear favourites after the result today and the pace they have shown so far," he said.

"But we are here to race otherwise it would be quite dull.

"We'll see what happens tomorrow. I think our starts are pretty handy, so we'll go from there."

Joining Vettel on the second row will be Red Bull's Max Verstappen who was 0.130 seconds back, but his teammate Pierre Gasly will be at the other end of the grid after a surprise elimination in the first qualifying session.

Gasly, formerly of Toro Rosso, said he had not anticipated how quickly the track would develop as his one minute 23.020 second-lap was only good enough for 17th place.

"We're not exactly where we'd like to be but session after session we're going in the right direction," he said.

"There were not many overtakes at last year's race so starting from where we are, it's going to be difficult but we will of course try and make it into the points."

Ferrari's Charles Leclerc took fifth place on the grid after going quickest in Q1, with the Haas pairing of Romain Grosjean and Kevin Magnussen 1.340secs and 1.613secs off Hamilton's pace respectively.

Rookie Lando Norris surpassed the expectations of many by clocking a lap of one minute 22.304 seconds to start eighth, while Kimi Raikkonen and Sergio Perez round out the top ten.

The 19-year-old said: "(I had) a lot of nerves going into it because I never managed to put it together in any other run I've done in P3 (third practice) or the whole of Friday so I'm just happy with how everything went."

The race starts tomorrow at 4.10pm local time (5.10am GMT).