The 27-year-old ran 32.58, the fifth fastest time in the world this year, to win the event ahead of Jamaica’s Mario Heslop (33.67) and Fabian Hewitt (34.42). Gardiner holds the World Record for the event with a 31.56 clocking in January 2022.
Gardiner, who finished top of the podium at the 2019 World Championships and 2021 Olympics, opened his season with a 33.03 effort to win his section of the 300m at the South Carolina Invitational on February 3.
The 2017 World Championship silver medallist is working his way back from a heel injury that forced him out of action for seven months, meaning he was unable to defend his World title in Eugene in July.
His last race before the layoff was on the 24th of June at the Bahamas Championships in Nassau where he won in 45.22.
Elsewhere, Guyanese Olympian Aliyah Abrams won the women’s 400m in 52.09 ahead of Jessica Gbai (53.64) and Alexis Williams (55.39).
The Bahamian produced a world-leading 31.78 to win the men’s 300m ahead of American Matthew Boling (32.58) and British World Championship silver medallist Matthew Hudson-Smith (33.82).
The 28-year-old's time was also the second fastest ever indoors, only trailing his 31.56 done at the same venue in 2022.
Gardiner, who also took gold at the World Championships in Doha in 2019, was on his way to another undefeated season in the 400m before pulling up with an injury in the semi-finals at the World Championships in Budapest last August.
In the women’s equivalent in South Carolina, Jamaican Charokee Young ran 37.38 for second behind American Quanera Hayes who won in an excellent 36.36. Tierra Robinson-Jones was third in 38.44.
Two-time Jamaican national 200m champion Andrew Hudson ran 6.74 to take top spot in the men’s 60m ahead of Miles Stephens (6.89) and Doniven Jackson (6.92).
In the field, Guyanese Limestone College senior Lloyd McCurdy jumped 14.50m to win the men’s triple jump ahead of Wingate’s Dequan Thompson (14.44m) and Limestone’s Trevon Jenkins (14.18m).
Parchment sped to a season’s best mark 13.15 for victory in the Men’s 110m hurdles ahead of the USA's current world leader Devon Allen (13.20) and Jamal Britt (13.30).
The Women’s 100m hurdles was won by the USA’s Alaysha Johnson in 12.50 ahead of Puerto Rican Olympic champion Jasmine Camacho-Quinn (12.52) and Jamaican 2015 World champion Danielle Williams (12.67).
Double Olympic sprint champion Thompson-Herah cruised to victory in the Women’s 100m in 10.93 ahead of Trinidad & Tobago’s Michelle Lee-Ahye (11.06) and the USA’s Shania Collins (11.08).
Bahamian reigning Olympic and World 400m champion Steven Gardiner won the Men’s 300m in 31.52 ahead of the USA’s Vernon Norwood (31.81) and Jamaica’s Nathon Allen (32.04).
2011 World and 2012 Olympic 400m champion Kirani James of Grenada was victorious in the Men’s one-lap event in a season’s best 44.70 ahead of Jamaica’s Sean Bailey (45.42) and the USA’s Trevor Stewart (45.50).
Jamaica’s Junelle Bromfield was third in the Women’s equivalent in 51.82 behind Americans Gabby Scott (51.42) and Olympic 800m champion Athing Mu (50.42).
Moving to the 400m hurdles, Jamaica’s Janieve Russell ran a season’s best 54.09 to win ahead of teammates Shiann Salmon (54.43) and Rushell Clayton (54.90).
In the field, Jamal Wilson of the Bahamas was victorious in the Men’s high jump with 2.22m ahead of the USA’s Jeron Robinson (2.17m) and Puerto Rico’s Luis Castro Rivera (2.17m).
