Michael Thornely struck an unbeaten 128 to boost Sussex 2nd XI on the opening day of their Championship match against Gloucestershire at Horsham.

The 20-year-old, who scored over 800 runs last year in the Seconds' title-winning season, stroked 20 fours and shared in an undefeated fifth-wicket stand of 109 with Tom Smith (38 not out).

Sussex, put in, lost wickets cheaply at the top of the innings with Andrew Hodd (7), Rory Hamilton-Brown (1) and Ben Brown (0) all dismissed quickly.

Sussex, who have already lost two Championship matches to the weather, could not get underway until 2.30pm and play went on until 7.30pm.