The gold was won by Paul Blake (Great Britain) in a time of 54.49. Notably, the race was so close that the fourth placed Krzysztof Ciuksza (Poland) was only two tenths of second behind Stedman.
Across at the pool, the Para-Swimmers were out in force again.
Jesse Reynolds made his second Paralympic Final in a row, finishing his heat for the Men's 100m Backstroke S9 in a time of 1:06.34 and qualifying in 7th place for the Final at 08.43am NZT.
Meanwhile, Paralympic debutant 15-year-old Tupou Neiufi qualified for her first ever Paralympic Final, finishing 8th fastest in her heat in a time of 1:15.68 to qualify for the Women's 100m Backstroke S9 Final at 08.50am NZT.
Rio 2016 Gold medallist, Mary Fisher, qualified 5th fastest for the Women's 200m Individual Medley SM11 Final in a time of 3:00.69, taking place at 10.00am NZT.
Rio 2016 Gold medallist Cameron Leslie finished qualified 7th fastest in a time of 41.30 for the Men's 50m Backstroke S5, at 10.51am NZT.
Rio 2016 Bronze medallist Rebecca Dubber competed in the heat for the Women's 100m Freestyle S7, finishing 9th in a time of 1:18.85, missing qualification for the Final by just under three tenths of a second.
Down at Pontal road cycling course, Paralympic debutant Fraser Sharp finished the Men's Road Race C3 just outside the Top 10, 2m:37s off the gold medal time of 1:49.11.
It was an exceptional result for the Tauranga local, who was only called up to the New Zealand Paralympic Team just over two weeks ago with Para-Canoeist Scott Martlew, after New Zealand was reallocated two more male slots for the Rio 2016 Paralympic Games following the suspension of the Russian Paralympic Team.
Sharp finished in 8th place in the Men's Time Trial C3 at the Rio 2016 Paralympic Games, in a time of 42:20.07.
Kiwis in action later today
Jesse Reynolds, Para-Swimming, 08:43, Men's 100m Backstroke S9
Tupou Neiufi, Para-Swimming, 08:50, Women's 100m Backstroke S9
Mary Fisher, Para-Swimming, 10:00, Women's 200m IM SM11
Cameron Leslie, Para-Swimming, 10:51, Men's 50m Backstroke S5
Stephen Hills, Para-Cycling, 04:00, Men's Road Race T1-2
Chris Sharp/Andrew May/Richard Dodson Para-Sailing 04:30 (Race 9, 10) Sonar
