Leicestershire 270 and 16 for 0 trail Sussex 430 (Alsop 182*, Pujara 77, Coles 70, Mulder 5-63) by 144 runs

Sussex gave themselves an opportunity to secure a second win of the season that may see them top the LV= Insurance County Championship Division Two table after forcing Leicestershire to follow-on.

The home side were dismissed for 270 in reply to Sussex's 430 on day three at Grace Road, Ari Karvelas and Fynn Hudson-Prentice taking four wickets each as Leicestershire fought back from 160 for seven thanks largely to Rehan Ahmed (59 not out) and Chris Wright (48) but still fell short. They are 16 without loss following on.

A superb unbeaten innings of 182 by Tom Alsop, who shared a stand of 169 with James Coles (70) for the fifth wicket, was responsible for putting Sussex in such a strong position despite Wiaan Mulder's five for 63 and Tom Scriven's three for 75 on a better day for Leicestershire's bowlers.

Should Sussex fashion a victory on the final day, they will move at least into clear second place in the table, top should Durham fail to secure victory over Yorkshire at Chester-le-Street, where they had two wickets in hand overnight but still required 33 runs to win.

Resuming in Leicester on 319 for four, Sussex's morning was developing along the lines they had hoped for the first 10 overs as Alsop and Coles raced along at almost five an over, extending their partnership by 48 to 169.

After 19-year-old Coles miscued Scriven to mid-off for a fine 70, the last six Sussex wickets fell in 17 overs for 63, which felt like an anticlimactic end to an innings they had hoped might top 500 runs, although 430 after being put in was hardly an under-achievement.

There was no dislodging Alsop, who overtook his previous best of 150, which he equalled against Leicestershire at Hove last summer, in the over after Coles's demise. But he needed more support and none was forthcoming.

Generating more swing than they had been able to find on Friday, Wright quickly had Oli Carter caught at second slip, Scriven dismissed Hudson-Prentice leg before with a ball that kept a tad low and Wright picked up a second wicket when Karvelas had no answer to a full delivery that took out his off stump.

Mulder wrapped up the tail to complete his second five-for in as many innings, having Henry Crocombe caught at slip, seeing off Bradley Currie for a 15-ball duck.

Nonetheless, Sussex had doubled their batting points from two to four thanks to Alsop's impressively measured and chanceless innings, and 430 looked a formidable total as Hudson-Prentice reduced Leicestershire from 70 for one to 79 for four by taking three wickets for one run in the space of 11 deliveries.

The former Derbyshire all-rounder brushed the outside edge to have Rishi Patel caught behind for a bright 34 and dismissed Colin Ackermann for a two-ball duck as the former Leicestershire captain was beaten by one that struck him on the back pad.

The current captain, Lewis Hill, suffered the same mode of dismissal, although perhaps unluckily given that his front leg looked well forward and across.

All this after Hudson-Prentice had appeared to have injured himself bowling his first ball, limping back to his mark flexing his left leg, although somehow by the end of the over, all was well. When he did take a rest, it was with figures of three for 12 from seven overs.

Deprived of both their leading wicket-takers, Ollie Robinson at England's behest and Nathan McAndrew to free up an overseas slot for Smith, there is an inexperienced feel to this Sussex seam attack.

Yet Cheteshwar Pujara, the Sussex captain, used his resources well, maintaining attacking fields and rotating sensibly. Karvelas and Currie, both making their first appearances of the season, removed Mulder and Australian wicketkeeper-batter Peter Handscomb in the first four overs after tea, leaving Leicestershire six down for 135.

Mulder was pinned in front by Karvelas before Handscomb, who has been the bedrock of Leicestershire's improved form this season, edged behind off Currie. When Crocombe produced the ball of the day to bowl Scriven, Leicestershire were 160 for seven.

Wright looked to hit his side out of trouble and threatened to do so, racking up 48 from 41 balls in an entertaining flurry of six fours and a six into the nets over square leg as he and Ahmed put on 69 for the eighth wicket.

But Karvelas, who had seen Ahmed dropped at gully on 34, removed Wright via an edge behind, putting the pressure back on Leicestershire with the follow-on target still 52 runs away.

Another 40 added by Ahmed with Will Davis took Leicestershire tantalisingly close, but Davis was taken at first slip off Hudson-Prentice and Ahmed's efforts to protect last man Josh Hull from Hudson-Prentice by taking a leg-bye off the fifth ball of a Karvelas over backfired as the last one hit Hull's front pad squarely in front.