Lewis Hamilton says it is "far too early" to talk about challenging for the championship this year after his win in Sunday's Hungarian Grand Prix.
Hamilton, 28, dominated at the Hungaroring despite the high temperatures, which have tended to trigger tyre problems for Mercedes.
"When you have a win like this, you get excited and think anything is possible and this shows it is," said the Briton.
"But it is still too early to say whether or not we can challenge."
Hamilton is still fourth in the title race following his first win of the season, but he has reduced the deficit to leader Sebastian Vettel to 48 points, with 225 still available over the remaining nine races.
Kimi Raikkonen finished second in his Lotus in Hungary to move up to second in the standings, 38 points behind Red Bull's Vettel, who was third at the Hungaroring.
Raikkonen is now one point ahead of Ferrari's Fernando Alonso, who finished fifth on Sunday.
Hamilton, world champion in 2008, said: "I know the guys [at the team] are working hard so that we can close the gap and I hope today is the first step in doing so, but we've got a lot of tough races coming up.
"I just hope that's not the last time my tyres work for me."
Mercedes have been suffering with heavy tyre usage all season, experiencing problems at nearly every race.
But the hot weather in Hungary, where the track temperature was more than 50C in the early part of the race, has given the team encouragement they might finally have got on top of the problem.
Hamilton said: "If we can be quick here in a race with these track temperatures, then I'm very hopeful that we can be competitive everywhere else, so this could be a really good turning point for us."
Alonso, meanwhile, insisted he can take the title fight to the end of the season despite Ferrari's disappointing form in Hungary.
The double world champion, who has not won since the Spanish Grand Prix in May, insisted his title chances were "not gone" after Vettel could only finish third in Hungary, but he admitted Ferrari needed to "win three or four consecutive races".
The Spaniard added: "Lotus, Red Bull and Mercedes are quicker than us and it is extremely difficult.
"But it's no different to other years in which we fought until the last race, so I'm sure we will fight until the last race."
Alonso, who sources claim has approached Red Bull to say he is available to drive for them next season, admitted Ferrari had been struggling to develop their car.
New parts were introduced for the British Grand Prix two races ago, but these were removed after they failed to work.
Following more problems in Germany, the car was reverted to what Alonso described as a specification from "some races ago".