Leeds also have a game in hand on their two nearest challengers but Grayson is keen to ensure complacency does not creep in at Elland Road.
He told the club's official website: "To be where we are at this stage is a real credit to the players and what they have done.
"They have worked ever so hard. We're not promoted now, but we've given ourselves a chance.
"The teams below keep putting the pressure on, though, and we have to be at it throughout the season."