World and Olympic medallist Shericka Jackson started the defence of her sprint double titles at the Jamaica Athletics Administrative Association (JAAA) National Championships with an impressive win in her first-round heat at the National Stadium on Thursday.

Jackson, who won the women’s 100m silver medal at the World Championships in Eugene, Oregon, last year, clocked 10.99 seconds (0.0m/s) to lead the qualifiers into Friday’s semi-finals and final.

Double Olympic champion Elaine Thompson-Herah ran a season best 11.12 seconds (0.3m/s) to win her heat and advanced along with National Under-20 record holder Alana Reid, who won her heat in 11.14 seconds (-0.6m/s) and Natasha Morrison, who was also a winner in 11.00 seconds (-0.4m/s).

Briana Williams, Kevona Davis, Sashalee Forbes, Ashanti Moore and Shockoria Wallace were among the qualifiers.

Earlier in the day, World Under-20 Championships medallist Roshawn Clarke signalled his intention with a personal best 48.91 seconds to lead the men’s 400m hurdles after Thursday’s semi-finals.

The bronze medallist in Cali, Colombia, last year caught Commonwealth Games champion Jaheel Hyde at the eighth hurdle and ran away to win. Clarke lowered his previous best of 49.35 and is just shy of both the National Under-20 record of 48.81 and the World Championships qualifying mark of 48.70.

Hyde, who is seeking his fourth national title and third in as many years, was second with 49.40, while former St Elizabeth Technical runner Robin Black was third with 50.24.

Assinie Wilson won the second semi-final in 49.67, the second fastest time in the round. He beat Shawn Rower (50.38) and Olympian Roxroy Cato (50.65).

Former World Under-18 champion Marvin Williams and Sean Kalawan also advanced to Friday’s final.

Andrenette Knight ran a hard first 300m to lead the women’s 400m hurdles qualifiers, clocking 54.41. She held off defending champion Janieve Russel (55.13) and Lashanna Graham (56.79).

Shiann Salmon won the first semi-final in 55.35, followed by Rushell Clayton (55.73) and Terice Steen (58.09), while Sanique Walker (57.75) and Kimisha Chambers (58.10) also advanced to the final.

Dwayne Graham won the men’s 5,000m title, clocking 16:30.52 minutes, beating Noel Ellis (17:15.78) and Jason Baker (17:27.76).