It had been expected the preselection contest would be tough, with Darwin doctor Peter Bourke up against Ms Griggs.
"I am ready to once again take the fight to Labor for the people of the Territory," she said.
Following the announcement of her victory Ms Griggs spoke with Dr Bourke.
"He said he would support me and while he was disappointed he understands the party processes," she said.
Mr Mills has angered some in the party because of recent decisions to raise electricity prices in the NT by 30 per cent.
The challenge never eventuated and Mr Elferink offered his resignation, but Mr Mills allowed him to retain his portfolio.