Fernando Alonso has admitted his Ferrari's lack of pace at the Singapore Grand Prix has been a "bad surprise".
"We were not happy with the performance of the car this weekend," Alonso said.
"This is a bad surprise but nothing we can do now other than score as many points as possible in the race."
The Spaniard, who is 37 points ahead of second-placed Hamilton in the championship, is the only man to win a race this season when he has not started from the front row.
But he said that although the Ferrari is normally more competitive in race trim, a win on Sunday was not on the cards and he was focusing on beating as many of his main title rivals as possible.
Lotus driver Kimi Raikkonen is one point behind Hamilton and one ahead of Red Bull's Sebastian Vettel, whose team-mate Mark Webber is a further 12 points behind.
Alonso said: "To win the race you need a little bit more on pace than we have at the moment.
"We cannot win with the pace we have now, but we are fighting for the world championship. Two in front, two in behind [on the grid] - Kimi and Webber behind, Vettel and Hamilton in front. We'll see if we can finish in front of three of them at least."
Alonso's pre-event hopes of battling for pole and victory were based on a series of upgrades to the car this weekend, but not all of them worked as hoped - the team abandoned a new rear wing design that was part of the package.
He told BBC Sport: "We more or less faced the same problems as last year on this circuit in this type of corners.
"So maybe it is the way of the characteristics of our design of car that in these particular corners, traction corners, we are not at the top so we need to improve on that.
"Some of the parts we brought here worked and some did not, so there is a little penalty there but not [the gap] we are from pole position."
Alonso looked competitive during the race-simulation runs completed by the teams in Friday practice, when he was quite close to Hamilton's pace, and he said he was optimistic that would carry into the race.
"On race pace [we] normally improve," he said, "and I guess here will be the same.
"Saturdays is our weak point of the weekend, we are never able to extract the maximum from the car over one lap.
"But in the race I expect a good pace and I expect a little bit less [tyre] degradation can put us in a fighting position. But podium I think can be [the] maximum target.
"To finish in front of some of the contenders will be our aim and waiting for a better weekend."