WORCESTERSHIRE made a solid response with 103-1 after removing Hampshire for 263 in LV= County Championship Division Two.
However, with only one day of action left, the teams are effectively playing for bonus points from a draw.
Sean Ervine notched 93 and captain Jimmy Adams a half-century as Hampshire recovered from a slow start to make a respectable first-innings total on day three at the Ageas Bowl.
The pair provided the cornerstone of Hampshire's 263 - a total that looked unlikely when labouring on 105-6 earlier in the day.
In reply, Worcestershire, for whom Jack Shantry took four wickets, passed the ton mark with skipper Daryl Mitchell and England's Moeen Ali at the crease on 44 and 27 respectively.
Hampshire started Tuesday's action, after a washed-out second day, on 37-3 having been inserted on Sunday, which had also seen play reduced by rain.
Adams resumed on 32 and soon progressed to his 50, bringing it up with a four to take his side to 65-3.
But two wickets from consecutive balls by Shantry pegged Hampshire back with Adams (67) caught by Alexei Kervezee and Joe Gatting (0) by Tom Kohler-Cadmore.
Another Shantry delivery subsequently ousted Will Smith (29), again via a Kohler-Cadmore catch, to leave Hampshire on 105-6 and looking in trouble.
The hosts steadied the ship, though, through Adam Wheater and Ervine.
They were 136-6 at lunch and the Wheater and Ervine partnership took them to 198 before the former (35) was caught by Kervezee off Gareth Andrew.
In the next over, the eighth wicket fell as Matthew Coles (1) was caught and bowled by Moeen.
Shantry took his fourth victim when David Balcombe (23) was caught by Ben Cox, leaving Hampshire on 237-9.
Ervine was the final man to go just seven runs shy of his ton, halted by a Kervezee catch off Charlie Morris.
Worcestershire's response saw Matthew Pardoe removed for 19 but otherwise it was a steady effort as Mitchell and Moeen remained unbeaten at stumps.