|LV= County Championship Division One, Ageas Bowl (day three)|
|Sussex 444 & 164: Wright 61, Tomlinson 4-37|
|Hampshire 231 & 181-4: Carberry 79|
|Hampshire trail by 197 runs|
|Sussex 6pts, Hampshire 3pts|
Hampshire fought back well to bowl Sussex out for 164 and leave themselves 197 runs to win on the final day.
The hosts resumed on 220-9 but only added 11 runs before James Tomlinson was run out by Ed Joyce.
Sussex tried to extend the advantage but only Luke Wright (61) contributed as Tomlinson (4-37) restricted the visitors to a lead of 377.
Michael Carberry (79) scored quickly to give Hampshire a promising start as the hosts reached stumps on 181-4.
Earlier, Sussex captain Joyce decided not to enforce the follow-on with Hampshire trailing by 213 runs after they were bowled out.
That decision initially looked questionable as Sussex fell to 71-6, with first innings centurion Ben Brown dismissed for nought by Tomlinson.
Wright then found an able partner in the shape of Ajmal Shahzad (28) as the pair shared a seventh wicket stand of 73, before Danny Briggs (3-27) broke the partnership and Sussex lost their final three wickets for nine runs.
Hampshire were not daunted by their Ageas Bowl record of 378 runs to chase with Carberry particularly aggressive in the final session.
The opener looked in fine touch as he struck 13 fours and a six to give the hosts impetus against Sussex's all pace attack.
However, after Carberry was dismissed by Michael Yardy, the hosts collapsed from 145-1 to 158-4 with James Vince and Liam Dawson both falling cheaply.
Will Smith (22 not out) and Adam Wheater (11 not out) steadied the innings before the close to set up an exciting final day with both sides in with a chance of victory.
Sussex cricket manager Mark Robinson: "We decided against the follow-on as the wicket was wearing and quite a bit of rough was beginning to appear.
"There was a thought it was going to get more up and down as it wore on.
"You are looking to bat them out the game but unfortunately what we ended up doing was give them some hope.
"Two batters have made the pitch look flat and then for a new batter it looks like hard work. That's what it has been like all the way through."
Hampshire bowler James Tomlinson: "We are very much in this game, and it has been a great effort that we are in this game from where we were this time last night.
"Wherever this game goes now we have shown the fight to play in this division.
"We can win tomorrow but we are going to have to bat well against a pumped-up Sussex side.
"We need a big partnership and a hundred from somewhere and if we can do that then we have a chance. It will go to the wire."