Striker Cisse returned from a three-match ban on Saturday to score his second goal in three games since his January move from Lazio.
But it was not enough to prevent a controversial 2-1 defeat at Bolton that sucked Rangers into the drop zone.
Cisse is not worried, though, and told his club's official website: "With this kind of performance, there's no doubt that we are going to stay up.
"We have to produce this every game and we have to score goals. We have to fight until the end and that's what we are going to do.
"I love challenges and I love the club already. I will do my best to help the club stay up because we belong in the Premier League now."