Whyte (20) broke the New Zealand junior record in April when he ran 46.25sec at the Australian senior championships in Sydney. It is also the Otago senior men's record.
The New Zealand senior men's record of 46.09sec was run by Shaun Farrell (Canterbury), in Wanganui in 1998.
Whyte will be pitted against the best 400m runners in the country in Hamilton in his last race in the country before heading to the United States.
In his last race in Dunedin before starting his athletics scholarship at the University of Texas in January, Whyte convincingly won the men's 400m at the Caledonian Ground on Saturday, in a time of 46.60sec, just 0.35sec slower than his Otago record. Clubmate Daniel O'Shea was second in 48.77sec.
It was only Whyte's second 400m of the season and follows the 46.71sec he ran in Dunedin two weeks earlier.
This is remarkably consistent running without serious competition. It suggests he could break the 46sec barrier and add the New Zealand senior men's record to his CV.
New international Julie Edmunds (Caversham) smashed her own masters women's aged 40 to 44 3km track walk record by 33sec with a time of 16min 10.80sec.
Edmunds has gained a lot of confidence after being named in the New Zealand senor women's team for the Oceania Race Walking Cup, in Hobart in February.
World masters 400m champion Liz Wilson (Hill City-University) broke her own Otago masters women's aged 50 to 54 100m record with a time of 13.45sec.
Wilson finished third in the senior women's 100m that was won by Fiona Hely (Hill City-University) in 12.64sec from Rebecca Gibson (Gore, 13.44sec).
Todd Bates (Taieri) had three throws over 50m when he won the junior men's hammer throw with 52.52m.
