Smyth's time, as he finished fifth at a meeting in Gainesville, was only .03secs outside his personal best.
The Eglinton man's performance was again inside the European Championship standard and he seems certain to be on the Irish team in Barcelona.
Double Paralympic champion Smyth has been training in Florida since January.
The visually-impaired athlete aims to compete at both the Olympics and Paralympics in London in 2012.
Smyth, 22, has continued to make steady progress since clinching double Paralympic gold in Beijing in 2008.
Last year, he represented Ireland at the European Under-23 Championships and finished the season on a high by winning the Irish 100m title and qualifying for this season's European Championships by improving his personal best to 10.42.
Smyth clocked 10.48 in the heats at the Gainesville meeting and then improved to 10.45 as he finished fifth in the final despite running into a .5m head wind.
Given that it's early in the season, Smyth looks on course to considerably improve his personal best this year and Paul Brizzel's Northern Ireland record of 10.35 could well be under threat.
Report from BBC Online
