The home side got off to a great start when a cross from the right was palmed out by Boro keeper Michael Gooch, only for Joe Christou to head the ball over him and into the back of the net.
Romford managed an equaliser in the 40th minute against the run of play when George Woodward fired in a free-kick from the edge of the box. But David Cowley took Thurrock into the break in front when he scored a second just three minutes later.
Mark Stimson`s Thurrock side continued to look impressive in the second half, but it wasn`t until the last minute of normal time that they managed to add a third for security when sub Charlie Cole`s low effort from 18 yards beat Gooch.
Ryman League
The win lifts Thurrock nine points clear of sixth-placed Tilbury and six behind leaders Cray Wanderers, although the Essex outfit possess no less than five games in hand on the leaders.
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