Lewis Hamilton picked up on Friday where he left off in Germany last Sunday by delivering the fastest times for McLaren in both opening free practice sessions ahead of this weekend's Hungarian Grand Prix.
The 26-year-old Briton, who won the world title in 2008, clocked a best lap time of one minute and 21.018 seconds, to top the speed charts and endorse the impression that he has regained top form after winning last weekend's race at the Nurburgring.
"It's a great feeling to start already on a high -- it wasn't really expected, (but) the climate is working for us, it's not as hot as it usually is here," he said.
"It's too early to say what's going to happen, but we can compete with the guys in the front. We do have a positive buzz in the team and that's great."
Button, preparing for his 200th Grand Prix back at the track where he registered his first win in 2006, said: "It was a trouble-free day, which is nice. We're definitely in the hunt so I'm very happy with the direction we've gone with the car and the feeling of the car."
Vettel, still downcast as he struggled to keep pace with the revived McLarens and Ferraris, warned his Red Bull team after the sessions that it was time they raised their game.
Vettel, a dominant winner of last year's Hungarian race, but pushed down to fourth on the grid in Germany last Sunday, believes Red Bull need to take a step forward in order to stay at the top.
He said: "It was pretty slippery at the beginning. Later on I felt ok in the car, but I think it is not like last year. It seems to be very tight. McLaren and Ferrari are very quick so I think we need to raise our game to make sure that we will find ourselves at the top as well."
He conceded that tyre management will not be easy this weekend.
"The most important thing to look out for is managing the tyres for one lap, but equally trying to get everything out of the tyres for the whole stint and not have them fall apart too quickly. It will be a tough one."
Webber, who crashed in the morning session and damaged his car, admitted his 'off' had been his own fault.
He said: "It was my mistake. I ran across the kerb - which has been there for a few years. Drivers still don't learn - we just go out there and push.
"I clipped the astroturf and hit the barrier, but fortunately it was only the nose that was damaged. We recovered pretty well this afternoon and got a lot of mileage in. The car ran well. Obviously it is a pretty tricky venue with tyres, so there's lots of information to go through."
On a relatively cool day at the Hungaroring, Nico Rosberg was seventh just ahead of his Mercedes team-mate and compatriot seven-times champion Michael Schumacher with Paul Di Resta ninth for Force India ahead of his team-mate Adrian Sutil.
Alonso, on his 30th birthday, dominated the early stages of the session with successive fastest times either side of a chart-topping lap from Button.
Alonso then broke the 1:22 barrier with a lap in 1:21.259 before Hamilton cut two tenths of a second off that time with half an hour remaining.
The Red Bulls did not appear to be too interested in going for outright pace at this stage and were working on long stints and tyre testing, until the final 10 minutes when they ran on the 'super soft' rubber.
All this left many close observers analysing the weather forecasts, temperatures and potential levels of tyre wear for clues as to the underlying performance potential for qualifying on Saturday.
Source: AFP Global Edition