Auckland seemingly had control of the one-day fixture at Lincoln but Martin is no quitter.
The Hearts had posted 261 for seven and the Sparks had slumped to 123 for four. Martin was the only batsman remaining who had the quality to seize back control of the game.
But even for a player of her calibre and experience, the task ahead looked too daunting.
However, Martin kept fighting until she was run out for 114 in the 49th over, with five runs left to win.
Victoria Holden had provided valuable support with an unbeaten innings of 39, and openers Leigh Kasperek (46) and Caitlin Blakely (34) got Otago's reply off to a solid start. But the Sparks fell painfully short at 259 for six.
Earlier, Auckland made a fast start, with Anna Peterson and Lauren Down putting on 65 for the opening wicket.
Peterson had rushed to 30 from 37 balls when she was bowled by spinner Morna Nielsen.
With regular captain Suzie Bates unavailable, Martin led the side and shifted from her regular spot behind the wickets to a place in the outfield.
Polly Inglis took the gloves and made an impact, stumping Maddy Green for 28 off the bowling of Kasperek.
The pair teamed up again to remove Down. The batsman had posted 75 before getting an edge through to the keeper.
At 187 for three, Auckland was well set up for a charge at the bowling.
Katie Perkins gave the innings some real momentum with a 36-ball half century. But she was out shortly after for 52. The new firm of Kasperek and Inglis had combined again to remove a real threat.
Perkins' departure helped Otago put the brakes on Auckland's innings. The defending one-day champion managed only 55 from the last 10 overs, despite beginning the final stretch with seven wickets in hand.
Kasperek's three for 37 from 10 overs represented a good day at the bowling crease, while Nielsen and England international Beth Langston finished with identical analyses of one for 44 from 10 overs.
Otago was well placed at 121 for one but Green picked up three quick wickets to leave Otago's innings in tatters.
All Auckland seemingly needed to do was pick up Martin's wicket and victory would probably be assured. The Hearts left it very late.
The sides will play another one-day game at the same venue today.
