With a 1-2-1 scorecard at round three of the series near Rotorua last weekend, Chase topped the podium in the class, although it was, in reality, only a five-point swing in Chase's favour.
Broad finished 3-1-2 at Rotorua, to end the day runner-up and keep his title hopes very much alive.
Chase will line up with his Total Oils Yamaha YZ125 on Sunday with everything to fight for and nothing to lose.
"I've still got a bit of work to do," he admitted. "I gained some ground last weekend and Taupo is my track, but it's going to be tough.
"I need to win at Taupo on Sunday and hope that Broad finishes the day lower than third. That might just do it for me. I'll just keep a level head and ride smart."
The dice rolls for the final time tomorrow, with racing set to start about 10am.