Lewis Hamilton says Mercedes must now brace itself for a 'big' Formula 1 title fight with Red Bull, despite the Brackley-based team comfortably winning the first two races of 2014.
The Briton secured Mercedes' second consecutive win of the season in the Malaysian Grand Prix, just a fortnight after Nico Rosberg triumphed in Australia.
But although Mercedes' competitive advantage seems large right now, Hamilton says he has no doubts that Red Bull is on the verge of a breakthrough that will make it part of the title fight.
"Sebastian [Vettel] was massively quick here," said Hamilton. "He was applying pressure to Nico.
"Looking at their pace, their car is just as quick as ours through the corners. They are just slower on the straights.
"I have no doubts at all that Renault are going to fix that and, when they do, you are going to see a big race between us and the Bulls.
"They still have a fantastic car. I have looked at the GPS - they are the same speed through all the corners.
"And also Ferrari are not too far off as well. It is going to hot up during the year."
Mercedes has been open about its surprise at Red Bull's progress rate since its winter testing woes, and Hamilton says the pressure from its rival is real.
It means Mercedes needs to work on an aggressive development push if it is to stave off the threat.
"I am going to keep pushing my team to continue developing and improving the car," he said.
"There are plenty of places we can improve upon, and I am sure everyone else is doing the same thing.
"This car was fantastic this weekend. I felt like I got every bit that I needed from it."
PRACTICE LESSONS KEY TO WIN
Hamilton reckons the lessons he took on board after Friday practice in Malaysia - when Rosberg had carried out a better race run - were key to him beating his team-mate this time out.
"On long run pace you could see our long run in FP2," he said. "Nico went a lap longer and was generally similar pace, so I was expecting that in this race.
"But from that running I learned a lot about where I could improve. It is one thing learning it, but being able to apply it doesn't always work.
"But here it worked and that is why I was pulling away."