The 32-year-old scored the Bluesbirds' winner as they overcame Blackpool 2-1 at Bloomfield Road on Saturday, allowing them to stretch their substantial lead.
After letting promotion escape them in recent seasons Smith is determined Cardiff can get the job done this term.
He told Wales Online: "It is ours to lose from here on in. We've worked our socks off to get to this point.
"There are a lot of good teams, but the consistency we have had so far has got us to this point and we are going to work as hard as we can to try and keep the 10 points barrier.
"The gaffer and staff won't let us get complacent. They are at us every day about doing things professionally.
"Nobody will take their foot off the gas. Everyone is desperate to play at the highest level, a lot haven't had that chance.
"It's driving us on so much that I can't see any complacency setting in."
Smith, who helped QPR to promotion in 2011, added: "The year we went up QPR were never 10 points clear, we had a five or six point gap at some points, but never 10. It's nice to have, but it's a lot of pressure too. Teams are going to give that bit extra to beat the team at the top of the table.
"Everyone has labelled Cardiff a 'nearly-team' over the last few years and it's tough. A lot of fans expect us to do well up to a point and then slip up, but we are trying hard for that not to happen this time."