Gloucestershire 198 for 9 (Hammond 42*, McAndrew 5-53) trail Sussex 455 for 5 dec (Pujara 151, Coles 74, Alsop 67) by 257 runs

Substitute fielder Tom Clark's direct-hit run out of Marcus Harris unlocked Sussex's bid to push for victory in their LV= Insurance County Championship match at Gloucestershire.

Australian opener Harris' dismissal, as his despairing dive failed to beat Clark's throw from midwicket, began a chaotic 10-minute period for the hosts in which Nathan McAndrew claimed the key wickets of James Bracey and Graeme van Buuren from successive balls on his way to a five-wicket haul.

Gloucestershire were suddenly four down at tea - after Chesteshwar Pujara's 58th first-class century had underpinned Sussex's 455 for five declared - as a rain-affected match came to life.

Sussex claimed a further five wickets in the final session, McAndrew finishing the day with figures of five for 53, as Gloucestershire slumped from 99 for one to 198 for nine at the close, still 257 runs behind.

Pujara ticked off the single run he needed his morning to reach his century before Sussex set about pushing for quick runs ahead of a pre-lunch declaration.

The visitors added 153 in the morning session with wicketkeeper Oli Carter contributing an unbeaten 59 off 78 balls, while Pujara reached 151 before he slapped Marchant de Lange to mid-off.

The skipper's next act was the call his batters in - after Fynn Hudson-Prentice also added a brisk unbeaten 29 from 19 balls - after reaching maximum batting bonus points to leave Gloucestershire's opener with a tricky period to negotiate before lunch.

Chris Dent and Harris managed that without concern and, while Dent played on attempting a square drive at Henry Crocombe in the afternoon session, the home side had looked set to reach tea without further alarm.

That all changed in the space of 13 balls before the break as first Harris, who had reached 37, turned the ball to midwicket and set off for a single he never made thanks to Clark's arrow shot.

McAndrew then pinned left-hander Bracey lbw from around the wicket, before van Buuren was snapped up at second slip from the very next ball to cue Sussex celebrations as they headed off for tea.

Sussex have won just once in each of the previous two County Championship seasons and, after an opening-round win over Durham, the then still-distant prospect of a second win in three games to start this summer appeared to galvanise their efforts in the evening session. McAndrew struck three more times during the session - Oliver Price and Zafar Gohar both edging behind to wicketkeeper Carter - before the Australian had De Lange bowled pressing forward in defence to complete his five-wicket haul.

In between time Crocombe's pace and bounce caught the defensive edge of Jack Taylor, Tom Alsop holding on at second slip. Crocombe then turned catcher as he held on at point when Tom Price slashed at Hudson-Prentice.

Gloucestershire's number four, Miles Hammond, remained steadfast while the wickets tumbled around him to finish the day unbeaten on 42, from 123 balls, to showcase the resolve his team-mates will require on the final day if they are to secure a draw.