Southland lock Hoani MacDonald collapsed with a suspected heart attack in his team's ITM Cup Championship division semi-final on Saturday.
The 34-year-old required vigorous CPR treatment for more than five minutes before he could be moved from the field and rushed to hospital.
Fairfax media quoted a stadium staff member as saying: "We got him back."
MacDonald, a former New Zealand Junior and New Zealand Maori representative, collapsed midway through the first half.
A Southland team spokesman said it was not known whether he collapsed during an incident on or off the ball, but spectators said MacDonald was treated for a suspected cardiac arrest after he fell clutching his chest.
"Macdonald was taken by ambulance from ECOLight Stadium to Middlemore Hospital," a New Zealand Rugby Union statement said. "He has been put in an induced coma and is stable."
In 2008, MacDonald left New Zealand to play for the Dragons in Wales before moving to Australia in 2011 to play Super Rugby for the Melbourne Rebels.