LV=County Championship Division Two, The 1st Central County Ground, Hove (day two):
Sussex 262 & 234-5: Clark 69, Coles 43*; Scriven 2-30, Ahmed 2-72
Leicestershire 108: Patel 48; Karvelas 4-14, Unadkat 3-23
Sussex (4 pts) lead Leicestershire (3 pts) by 388 with five wickets standing
Sussex revived their promotion challenge, dealt Leicestershire's a blow and ensured that leaders Durham will definitely be playing in Division One of the County Championship next season after dominating day two at Hove.
Sussex's seamers exploited a green-tinged pitch to take eight wickets for just 40 runs in the morning session as Leicestershire were bundled out for 108 and conceded a first-innings deficit of 154.
Leicestershire's failure to earn any batting bonus points against Sussex meant Durham were promoted from Division Two with two games to spare.
To join them Sussex probably need to win their three remaining matches - a tall order for a side with just one victory all season - but their batters made sure their advantage was not squandered.
Tom Clark scored 67 to help his side reach 234-5 at stumps, a lead of 388, with James Coles undefeated on 43.
If Leicestershire do miss out on promotion they will reflect ruefully on a miserable collapse including a spell when they lost four wickets in 29 balls for just five runs after resuming on 68-2.
First to go was Colin Ackermann, beaten by Indian left-armer Jaydev Unadkat's late inswing.
Undakat then moved one the other way to find Umar Amin's edge and he was expertly backed up at the other end by Ari Karvelas.
Rehan Ahmed was athletically caught behind by the tumbling Ollie Carter, poking outside off stump, and Ben Cox shouldered arms in Karvelas' next over.
There was a recovery of sorts by opener Rishi Patel and Tom Scriven who survived nine overs before another collapse saw the last four wickets fall for 16 in 6.1 overs.
Fynn Hudson-Prentice was rewarded for his exemplary wicket-to-wicket line as Scriven edged behind and Chris Wright lost his middle stump to an inswinger two balls later.
Patel, who had watched six wickets fall at the other end on his way to 48, decided, with only the tail for company, to attack Karvelas but a mistimed drive was superbly caught by Cheteshwar Pujara.
Unadkat finished things off when Matt Salisbury slogged him high to mid-wicket.
Tom Haines and Clark launched Sussex's second innings with a stand of 49 but, having done the hard work against the new ball, Haines (34) frustratingly spliced a pull off Wright, who is joining Sussex next season, to mid-wicket.
Ahmed was soon into a long spell down the slope and he picked up wickets either side of tea. Tom Alsop (31) unluckily played back but the ball rolled down onto his stumps while Clark, who batted for three hours for his 67 which included 10 fours, was leg before to one that might have been sliding down the leg side.
Leicestershire kept plugging away and Scriven took two wickets in the last hour - Pujara under-edged a ball that was too close for him to cut, and wicketkeeper Cox pulled off an outstanding leg-side stumping to remove Carter, but it was a rare highlight on a sobering day for the Foxes.
Report supplied by ECB Reporters' Network.