"Bit by bit, I've got to try and claw points from him," Hamilton said.
"He's got quite a good lead. I've got competitors quite close to me too, just a few points behind. Tomorrow is quite an important day."
Hamilton 'really happy' with pole
Hamilton's performance in qualifying was hugely impressive - he was more than half a second quicker than Maldonado - and he said he was very satisfied with what was "a really good lap".
But he said he expected a tough race on the demanding Singapore track in the equatorial heat and humidity.
"It's roasting," he said. "It's 30-something degrees and the humidity is high, we're in these thermal long tops [fireproof underwear], [driving] suit on and balaclava, we're sweating like crazy. I'm drinking four or five litres a day or something silly like that. The race is going to be tough."
Singapore Grand Prix 2012, day three
Sunday, 23 September: Live race coverage on BBC One from 12:10 BST & BBC Radio 5 live from 13:00 BST & live text commentary online from 12:00 BST. Highlights on BBC Three at 19:00 BST.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.