Middlesex, now hitting form after a sluggish start, had Richard Johnson to thank again as Sussex were dismissed for 228. After his perfect 10 two weeks ago, he took 4 for 10 in just 29 balls as Sussex lost their last six wickets for 42 runs. In reply, Middlesex were 23 for 2.
Kent's Min Patel, who bowled unchanged for 27 overs, took his wickets tally to 59 with three more against Worcestershire, who were all out for 202.
Brian Close and David Acfield, the Essex chairman, are the two candidates to replace the retiring Ossie Wheatley as chairman of the Test and County Cricket Board's cricket committee.