Smart had run 8:24.84 at Millfield last weekend, but, pushed by big rival Will Barnicoat in Buckinghamshire, he knocked more than eight seconds off that time on Saturday to take overall victory in 8:16.24.
That was nearly four seconds inside British Athletics’ European Under-20 Championship qualifying standard and ranks him sixth nationally.
The battle for GB spots in the 3,000m for Tallin is going to be fierce with an incredible 10 athletes inside the qualifying standard.
The trials for that event will be held at Manchester over the weekend of June 26-27. Smart will be competing there and also at the England Athletics U23/U20 Championships in Bedford, which will act as trials for other disciplines.
Meanwhile, City of Plymouth international David King continued his build up for the Olympic trials by running 13.57 seconds to take sixth place in a nine-strong elite 110m hurdles final at the World Athletics Continental Tour Gold Level event in Hengelo, Netherlands.
It was King’s second fastest run of the season and followed on from him taking silver at the European Team Championships the previous weekend.