Only colleague Nico Rosberg finished within 30 seconds of Hamilton as Mercedes continued the dominance the team enjoyed last season.
But Hamilton said: “We definitely cannot back off because I’m sure people are going to be pushing. Hopefully we’ll keep finding ways to improve. Just because we had that gap it doesn’t mean we’ll be cruising. There’s still a long way to go.”
Rosberg, who pushed Hamilton for the title all the way to the final race last year, finished second in Melbourne yesterday, just 1.3 seconds behind his team-mate, and believes he can overhaul him this season.
“Lewis did a fantastic job,” said the German. “He drove like a world champion all weekend so I couldn’t quite beat him, but for sure I was trying every single lap, all the way to the maximum, and I will do all year. I will give him a big run for his money and hopefully beat him.”