The right-handed Guptill bludgeoned 93 off just 30 balls as the Black Caps cantered to a 10-wicket victory over the Asian side at the Hagley Oval to go two-nil up in the five-match series.
Guptill brought up his half-ton off just 17 balls, one ball shy of the world record held by South Africa’s AB de Villiers, but he never knew about the record while hitting the ball to all corners of ground.
The 31 year-old though now holds the record for the fastest fifty by a New Zealand player in ODIs, beating Brendon McCullum who took 18 balls against England at the World Cup earlier this year.
Guptill said: “I was trying to hit as many runs as I could, as quick as I could. The plan was always to go out and be aggressive, and create a strike rate at the top of the innings.
“The first time I thought about the record was when the umpire said to me: ‘You’ve got two balls to get it or something like that.’ That’s the first time it came to my head.”
The third ODI of the series takes place at the Saxton Oval in Nelson on Thursday.