The big question after Malaysia is: has Ferrari really caught Mercedes?
After Sebastian Vettel's breakthrough win in red on Sunday, Mercedes figures admitted to being surprised their dominance of Melbourne has been so quickly reined in.
Team boss Toto Wolff described it as a "wake-up call".
"I don't think it was a wake-up call," championship leader Lewis Hamilton insists. "But I think everyone can always do with, not a kick, more like a pinch."
Some think Malaysia was just a one-off. Huge track temperatures were recorded all weekend, and the Ferrari undoubtedly handled them better with the Pirelli tyres.
There were also tactical errors by Mercedes.
"We weren't particularly good on radio messaging," Wolff admitted. "We had a couple of weird calls."
Also on the strategy front, Mercedes might be accused of having played too conservative a game, given its huge dominance in Australia just two weeks earlier.
Wolff said he might now press the button to speed-up technical developments ahead of China, and said another re-think will also take place at Brackley.
"Maybe with our very 'fair-play' ideas ... maybe in future we need to make decisions that could be a little unpopular with the Germans or the English," he is quoted by German-language reports.
He is referring to the fact that Mercedes likes to give Hamilton and Nico Rosberg total equality when it comes to race strategy.
But on Sunday, a better tactic might have been to split the strategies so that one Mercedes was always within sight of Vettel's Ferrari.
Former F1 driver David Coulthard admits Mercedes has been given a lot to think about after Malaysia.
"This is a new test for the Mercedes management," he told the Telegraph, "but the momentum is still with them."
Former Ferrari driver Felipe Massa agrees that the Maranello team cannot yet celebrate having bridged the formerly massive gap to Mercedes.
"Mercedes has the faster car," he is quoted by Auto Motor und Sport, "and Ferrari uses the tyres better.
"That was the key in Malaysia," said the Williams driver.
But another key, Massa added, is a big step made over the winter by Ferrari on the 'power unit' front, which may not have been matched by Mercedes.
"At the moment we do not feel more power than last year," said the Mercedes-powered driver. "But you can also see it with the Sauber - Ferrari has taken a giant step."