The ease with which Lewis Hamilton and Mercedes dominated Friday practice in Melbourne left a few people shell-shocked.

What had happened to the speed Ferrari had shown in Barcelona testing, which had boosted everyone's hopes that the 2017 World Championship would have a different look to it than the previous three years?

It was a little closer on Saturday, but Hamilton still had a significant edge over Sebastian Vettel. And fortune continued to go Hamilton's way at the start of the race – which hasn't always been the case in the recent past.

When car #44 emerged from the first corner safely in front it appeared that Vettel's best chance of turning things around had already gone.

And yet 57 laps later it was the Ferrari that crossed the line in front, Hamilton and his team left looking for answers after a decision to make an early pitstop turned the race on its head.

Battle lines drawn

Melbourne showed us that our prayers have been answered, and that we will have what Toto Wolff called a "hell of a ride" as Mercedes and Ferrari do battle this year.

Red Bull isn't quite there at the moment, but its package does have potential if Renault's planned upgrades do what they are supposed to.

But for the moment it's about silver and red, and it promises to be a knife-edge contest which ebbs and flows by the weekend, with track characteristics, set-up and tyre usage paying a role.

In Melbourne much was riding on the start, and in contrast to last year it went to plan for Hamilton. Yet despite clearly giving it everything he had as he pushed hard in those opening laps, Lewis didn't pull away.

Instead it took him five laps to eke his advantage out to more than a second. The gap grew to 1.8s by Lap 11, but not only was Vettel still there, he then began to reel the Mercedes in again.

Lewis was struggling on the ultrasofts in the relatively warm conditions that followed the 4pm start, to the extent that he suffered from the tyres overheating. Historically that has led to their performance dropping off, and drivers struggling to get them back.

One of the key challenges set by the FIA for Pirelli in the 2017 'target letter' was to stop that happening, and the general feeling was that they had succeeded. That was certainly the Pirelli view at the very least, and there was little or no talk of overheating issues up and down the pitlane. Except at Mercedes.

Something in the set-up and the way the W08 used its tyres in Melbourne was pushing them over an edge that nobody else seemed to find – and by running flat out from the start, rather than pacing himself, Lewis got into trouble.

And it wasn't just a Hamilton problem; despite dropping out of Vettel's slipstream in third in order to protect his tyres, Valtteri Bottas also suffered badly with overheating.

"I believe that these tyres have a narrow window," said Toto Wolff. "And you need to keep them in that window in order for them to perform well.

"If you're below the window or above the window, you lose performance. So that is different to the last years, it needs a new calibration for all of us and understanding of the tyres."

Vettel piles on the pressure

The bottom line was that with the pitstop window approaching, Vettel was right on Hamilton's tail, and the leader was under serious threat.

The fear at Mercedes was that the Ferrari would pit first and that Seb would have much better pace on his out-lap than Lewis could manage with his older tyres. So the decision was made to counter that by coming in earlier than had been planned.

So, at the end of Lap 17, and much to the surprise of Ferrari and strategists up and down the pitlane, Hamilton peeled into the pits.

"The Ferrari was the quicker car, the way Sebastian held on to Lewis, on his gearbox," said Wolff.

"We were pushing flat out and we were just not able to pull away. There was the risk of the undercut, and we also thought that the tyres wouldn't last any more. And all that led us to the decision to pit to avoid the undercut.

"And then coming out behind Max, who was fighting his own race, just lost us the race..."

Hamilton did indeed emerge behind Max Verstappen. Mercedes obviously knew that Lewis would find himself behind the hardest man in F1 to overtake, but made the call anyway.

And that is perhaps an indication of the impact that pressure from a rival has on the split-second decision making process at a team that, over three dominant years, has become so used to juggling the strategic interests of its two battling drivers internally.

The chosen option was a valid one at the time – to pre-empt a possible Ferrari strategy – but it just didn't work.

"You're trying to take on board all the information you have," said Wolff.

"What you see in terms of tyre temperatures and grip levels and sliding, and then of course how the driver perceives it. And all of that leads to a decision. And in that case it was probably a couple of laps too early.

"We actually thought that, we had hoped for Max to pit earlier, and then being in free air, so it was a combination of variables that went against us."

It wasn't just about Verstappen, either. Even if the Dutchman had pitted or pulled over and waved Lewis by, Kimi Raikkonen was a little further up the road – and Ferrari just had to keep him out riding shotgun to ensure that Vettel was safe up ahead.

Verstappen plays his part

Meanwhile, Hamilton clearly wasn't happy to find himself behind Verstappen. He was urgently told, "we do need to get past Verstappen," while also that he was "still safe to Vettel."

That was strictly true at the time, but it seemed a slightly conflicting message for a driver to receive in the heat of battle – do I have to take a crazy risk to pass or not?

"At that stage we were 1.7s safe to Sebastian," said Wolff. "So that was live communications of what it is. And we didn't know when Max was pitting, and we didn't know how long Sebastian would stay out, so it was the complete set of information."

Max was never going to make it easy, and as expected the 2017 aero package has made it harder than ever to overtake. As Hamilton noted on the radio: "No way can I get past this guy..."

And gradually, over the course of four or five laps stuck behind Verstappen, the situation with Vettel became "not safe".

The Ferrari came in on Lap 23, after six laps of running in clear air on his old ultrasofts. Despite losing time behind Lance Stroll on his in-lap, Vettel emerged just in front of the Red Bull and Ferrari, surviving a squirrelly moment at Turns 1-2.

Just to rub salt in the Mercedes wounds, Hamilton spent a further two laps stuck behind Verstappen, as the Red Bull driver stretched his old tyres to the limit. By the time Max pitted and Lewis was clear, the gap had grown to 6s, and it was all over. Vettel was away and gone in front.

And he could now show the true pace of the SF70H that he couldn't fully use in the early part of the race when he was in Hamilton's dirty air.

Damage limitation for Mercedes

The Mercedes was much more comfortable on the soft tyres and with the track temperature dropping – but Lewis now had to make his tyres run six laps longer to the flag, so there could be no heroics.

The gap drifted out to more than 10 seconds, and he was told to turn down his engine. Meanwhile Bottas caught right up with his teammate after a solid first outing with his new team, as a their tortoise and hare races converged.

"I think I had more pace than them in the second stint," said Hamilton. "It's just that I stopped so much earlier that I really didn't know how long the tyre was going to last.

"I didn't want to push to close the gap knowing that I couldn't overtake anyway, and then find I've run out of tyres at the end and lose second place. So it was really, I think, once I came out behind the other car, came out behind Sebastian, it was really about damage limitation."

Damage limitation for Mercedes on a day when the start was perfect, there were no incidents or mechanical problems, and no bad weather interventions? That shows just what a fight the triple world champions now have on their hands.

And it means many more marginal strategic decisions will have to be made this year.

For full race analysis and detailed review of the Australian GP, see GP Gazzette.