Marcus Trescothick continued to frustrate Sussex on the second morning of their County Championship clash with Somerset at Hove.

The former England opener reached 78 not out at lunch, after resuming on 39 overnight, to guide Somerset to 174-4.

It is his highest score in the County Championship since making a century against Worcestershire in September 2012.

The only joy for Sussex during the morning session was the wicket of night-watchman Alfonso Thomas who was trapped lbw by Chris Jordan for four.

They could have made further inroads into the Somerset batting order if they had held onto three difficult catches behind the wicket.

Alviro Petersen was twice given a reprieve with Ed Joyce putting him down at third slip off Jordan when he had made just seven and Ben Brown missing a thin edge off Ashar Zaidi when on 29.

Trescothick was also let off the hook when he was on 65 as Jordan was unable to take a low chance at slip off Zaidi.

Trescothick and Petersen have so far put on 85 for the fifth wicket with Petersen unbeaten on 46 at lunch.