The Sri Lankan was in brilliant form, reaching 50 off 32 balls and going on to make 95 off 96 balls in 111 minutes, with one six and 16 fours. He was eventually trapped leg before by Graham Gooch, the first of two wickets for one run in 11 balls by the former England skipper.
However, it was Ronnie Irani who did most of the damage with his medium- pacers. He finished with a career-best five for 62 in 20 overs, with his last two wickets coming off successive balls. Kent, who had followed on 294 behind, were always struggling to stave off a big defeat.
Trevor Ward (64) and Nigel Llong (43) both did well before De Silva took centre stage in a thrilling partnership of 76 off 13 overs with the left- handed Llong, of which the Sri Lankan's share was 56.
Irani was indebted to a superb catch at backward point by Mark Waugh to dismiss Llong, the Australian diving to his right and taking the ball one-handed. Waugh completed Essex's victory by trapping Marsh leg before.
Richard Harden scored his fifth Championship century of the season to put Somerset in a strong position against Leicestershire at Weston-super- Mare.
Harden battled for over five hours to score a typically resolute 124 off 218 balls, with 19 fours. He shared a valuable third-wicket stand of 198 with Keith Parsons as Somerset closed the third day on 299 for 5, with a lead of 242. Parsons hit his best ever championship score of 78, collecting 12 boundaries in a 178-ball innings.
The pair turned the match Somerset's way after Leicestershire took a first-innings lead of 57 when bowled out for 350 in the second over of the day.Reuse content