This is the last full-field event on the tour this year and will determine the 125 players who will automatically earn playing privileges for next season.
Singh, the world's top-ranked player, is seeking his ninth victory of the season.
"I'm not coming in here goal-oriented," said Sluman, 47, who ranks 79th on the money list this year. "I think if I just go out and just keep playing solid golf, maybe something good will happen."
Sluman capped his round by hitting a 7-iron from a fairway bunker to within a foot of the hole for birdie.