The English Schools’ cross country champion ran 1:59.04 to finish second in the B race and fastest under-17 out of all the heats.
Smart’s run came just 10 days after he had also set a new 1,500m PB of 4:02.89 to win the South West Schools’ intermediate boys’ title at the same venue.
City of Plymouth’s Dean Smith was second in the A race on Tuesday night at Exeter in 1:57.21.
There were personal bests over the same distance for Tavistock teenagers Will Russell (2:10.79), William White (2:16.86), Ben Wilkinson (2:17.85), Amelia Riggott (2:22.42) and Tilly McDowell (2:22.03).
In the 1,500m, Tavistock under-15 athlete Ewan Dix went under five minutes for the first time. He smashed his PB with a 4:52.32 run. There were also PBs over the same distance for his club colleagues Matilda Riggott (5:06.13), Elyse Kedzior-MacDonough (5:06.57) and Charlotte Tilney (5:24.34). City of Plymouth’s Talia Sullivan also claimed a PB with 5:10.55.
Meanwhile, City of Plymouth’s Victoria Weir ran her fastest 1,500m time for two years with a 4:35.60 run on Wednesday in the University of Birmingham’s Ivy League Match with Harvard & Yale.