Sebastian Vettel won the season-opening 2018 Australian F1 Grand Prix for Ferrari - but it was more by racecraft than outright speed, something Vettel is all too conscious of. Picture: Brandon Malone / Reuters

Melbourne, Australia - Sebastian Vettel won the first round of what could be a long and lively Formula One title fight with Lewis Hamilton on Sunday but the Ferrari driver may be the one with more to worry about as they leave Australia.

Champion Mercedes messed up in Melbourne, its mistake denying Hamilton what had looked a nailed-on victory from pole position, but they also left rivals in no doubt about their pace.

"At the moment we're a bit worse off," Vettel told reporters after repeating 2017's opening win thanks to a pit stop during a virtual safety car period that wrong-footed Mercedes, whose data wrongly indicated Hamilton had him covered.

"Last year we had more pace at this point. If you look at the gaps the whole weekend, we're not yet a true match," added Vettel, who is vying with Hamilton to become a five-times champion.

"I think if you look, and you are fair, then Lewis was fastest whereas last year I think we were fastest and it was very, very close."

In 2017, Vettel led from Melbourne to Monza before his challenge imploded.

Hamilton took pole on Saturday with one of the great qualifying laps of his career, lapping a huge 0.664s quicker than Ferrari's Kimi Raikkonen.

The time may have flattered him, with the Briton producing a near-perfect lap while Vettel would doubtless have been closer had he not made a mistake, but rivals also pointed to Mercedes' qualifying 'party mode' engine setting with concern.

"Mercedes is playing with everybody," Red Bull motorsport consultant Helmut Marko was quoted as saying after qualifying. "With that engine, nobody can beat Mercedes. They're in a different world."

Despite the pessimism, and the absence of Red Bull drivers from the year's first podium, Melbourne did not dispel hopes of a three-way team battle.

Fastest lap 

Local hero Daniel Ricciardo, who finished fourth after starting eighth following a grid penalty, set the fastest lap of the race for Red Bull and was right on the tail of Raikkonen.

Red Bull team principal Christian Horner insisted: "We're convinced that we had a better car than Ferrari, though the Mercedes still probably had something in hand."

Melbourne is a difficult circuit to overtake on but Bahrain is next up and more open. Vettel won there in 2017 when it was the third race of the season but Hamilton will also fancy his chances.

"We still got second," he said on sunday. "It feels like a dark cloud but it's not. We have a great car, we are still the world champion and with a couple of adjustments we can win the next race."