Lloyd (17), a pupil at St Andrews College in Christchurch, swam 1min 09.56sec to break the women's aged 17 100m breaststroke record.
She was competing with 353 swimmers at the 30th annual Neptune Queens Birthday Swimming Carnival.
The old record of 1min 09.64sec was swum by Anna Wilson (Otago) in 1995. She was a member of Duncan Laing's squad at that time.
Wilson joined Otago swimmers Danyon Loader and Scott Cameron at the Atlanta Olympics in 1996. It is Lloyd's goal to represent New Zealand at the Rio de Janeiro Olympics in 2016.
Lloyd's performance took long-term Otago swimming administrators back to the glory days of coach Duncan Laing, when New Zealand records were set frequently at Moana Pool.
National Masters records are broken from time to time but records in other grades are rare.
Lloyd is New Zealand's best female breaststroke swimmer and has won several New Zealand open titles.
But she has just returned home from a holiday in the United States and did not expect a record at this time.
''It's pretty exciting to get a record at a meeting like this,'' Lloyd said.
''It's another step forward to my big goal of going to the Olympics.''
Lloyd broke her first New Zealand record at the age of 12 and this was her seventh.
The performance pleased her coach Brigitte Mahan.
''Natasha's got the potential to go all the way,'' she said.
Lloyd begins a four-year swimming scholarship at the Auburn University, Alabama, in the United States, next January.
Lloyd won four other senior women's events at the weekend - a personal best 100m freestyle (57.02sec), 200m freestyle (2min 04.88sec), 50m breaststroke (32.42sec), 200m breaststroke (2min 32.66sec).
Kate Godfrey (Neptune) gained the most points in the senior women's grade with 86 points and was followed by Lloyd 70 and Kelly Scammell (Aquagym, Christchurch) 51.
Godfrey (19), who is in heavy training for next month's World University Games in Russia, won eight women's senior events.
She beat Lloyd in three events but the most significant was in the 200m individual medley that she won in 2min 16.17sec. Lloyd was timed at 2min 21.32sec.
Lloyd also beat the other top Canterbury swimmer Sophia Batchelor (Aquagym) in two events.
Godfrey won the 50m backstroke in 29.36sec and Batchelor was timed at 30.01sec.
She blitzed Batchelor by six seconds when she won the 200m backstroke in 2min 13.27sec.
Otago's top male swimmer Kurt Crosland (Neptune) comfortably won the senior men's grade with 90 points and was followed by Neptune clubmates Nick Tyrrell 63 and Adam Simpson 53.
He was the dominant male swimmer and won 10 events. This included breaking Matthew Glassford's Otago senior men's record in the 100m breaststroke.
Crosland broke the record in the heats with 1min 03.96sec and lowered it again in the final with 1min 02.98sec.
Since returning to competitive swimming 30 months ago, Crosland has broken 60 Otago open men's records.
His other top performance was in the 100m freestyle that he won in a personal best time of 50.43sec from Tyrrell (51.62sec). That record is held by double Olympic gold medallist Loader.
The boys aged 12 and 13 100m individual medley record kept changing hands.
Tame Govaerts (Zenith) took the record with his heat time of 1min 05.47sec. He held it for three minutes before Courtland Ellis (Neptune) broke it in the next heat with his time of 1min 05.02s.
Fourteen-year-old Campbell Pearson (Alexandra) won the boys aged 13 and 14 final in 1min 02.41sec and was followed home by Govaerts (1min 03.79sec) and Ellis (1min 03.90sec). Govaerts now holds the record.
Govaerts also broke three other records in the 12 and 13 year age group - 50m backstroke (30.81sec), 50m breaststroke (32.06sec) and 100m breaststroke 1min 10.11sec.
The other Otago record at the championship went to Jack Divers (Neptune) in the boys aged 10 and 11 breaststroke (1min 26.52sec.).
The winners of the other grade points were: Jessica Scott (Kiwi) girls 10 and under (88 points), Matthew Moore (Timaru) boys 10 and under (64 points), Kyra Forrest (Wharenui, Christchurch) girls 11 and 12 (121 points), Gordon Forrest boys 11 and 12 (104 points), Caitlin Deans (Neptune) girls aged 13 and 14 (77 points), Campbell Pearson (Alexandra) boys aged 13 and 14 (95 points), Aleisha Ruske (Neptune) girls aged 15 and 16 (73 points), and Henry Muskee (Aquagym) boys aged 15 and 16 (71.50 points).
Neptune
30th Annual Swimming Carnival
NZ record: Natasha Lloyd (North Canterbury) women's aged 17 100m breaststroke (1min 09.56sec).
Otago records: Kurt Crosland (Neptune), Tame Govaerts (Zenith), Courtland Ellis (Neptune), Jack Divers (Neptune).
Leading teams: Neptune 1566.50 points, Wharenui (Christchurch) 731.50, Aquagym (Christchurch) 686, North Canterbury 396.50, Queenstown 229, Timaru 193, Ashburton 187 (top for clubs with 10 or less swimmers), Oamaru 178.50, Jasi (Christchurch) 146, Kiwi 145.
