Bromell's form suggests he is firmly in the frame as a potential 100m gold medallist in Tokyo, where world champion Christian Coleman will be absent because of a doping ban. Image Credit: Reuters

Florida: American Trayvon Bromell underlined his credentials as the Tokyo Olympics 100 metres gold medal favourite by running the fastest time this year of 9.77 seconds at the New Life Invitational in Miramar, Florida.

Bromell becomes the ninth man to dip under 9.80 seconds, slashing nearly one-10th of a second off his personal best of 9.84.

Marvin Bracey of the United States was second in 9.85 followed by Chris Royster in 10.08.

Personal best

Reigning Olympic double sprint champion Elaine Thompson-Herah won the 100m and 200m events, clocking 10.87 and 22.54 seconds, respectively.

Bromell exploded onto the athletics scene in 2015, when he ran a personal best time of 9.84sec for the 100m before his 20th birthday - the fastest time ever run by a teenager over the distance - before later claiming a bronze at that year’s World Championships in Beijing.

After winning 60m indoor world gold in 2016 he suffered disappointment at the Rio Olympics, finishing in eighth place in the final won by Usain Bolt.