He made his One Day International debut for New Zealand on the 10th January 2009 against the West Indies in Auckland, becoming the first New Zealander to score a century on his one-day debut. He reached the landmark with a huge six off the bowling of Chris Gayle. His score of 122 not out is the highest debut score in New Zealand ODI history, and second highest debut score ever. He also gained the highest ODI score for a New Zealander against the West Indies and became the first cricketer from his country to carry his bat through a completed innings.
He currently plays cricket for the Auckland Aces. He plays in Auckland cricket club competition for Suburbs New Lynn.
At age 13, Guptill was involved in a forklift truck accident and lost three toes. When he was in the hospital, his father asked Jeff Crowe if a New Zealand player could visit him. Stephen Fleming, the New Zealand captain at the time, visited him at the hospital the next day. On his ODI debut, Guptill surpassed Fleming's record for the highest individual score by a New Zealand debutant.