Carl Hopkinson and Murray Goodwin fell agonisingly short of centuries but helped Sussex to 318-5 after being put in by Surrey on the second day at Hove.
After Wednesday's washout, Surrey chose to bowl on a slow, unresponsive wicket.
Hopkinson looked set for an elusive maiden century until he slammed a full-toss from Usman Afzaal and gave the occasional spinner a low return catch.
He had shared 126 in 34 overs with Murray Goodwin, who was denied his 35th ton for Sussex when he edged late on.
On a sunny but fresh day at Eaton Road, Sussex had reached 87 without loss when West Indian left-arm seamer Pedro Collins bowled Chris Nash attempting a pull on 46.
Former Sussex spinner Saqlain Mushtaq then ousted Michael Yardy in the 10th over after lunch when the umpires confirmed that the left-hander had edged his sweep into his boot before it looped up to slip.
The prolific Goodwin opened his account by driving his first ball from Saqlain to the square cover boundary and hit a total of six fours in reaching fifty from 80 balls.
Skipper Chris Adams struck Collins to the cover fence when the new ball was taken and shared 37 in 10 overs before he was trapped in front.
Goodwin's entertaining knock ended on 98 when he followed a delivery from Australian pace bowler Matt Nicholson and edged a straightforward catch to wicket-keeper Jonathan Batty.
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