A weakened Warwickshire still showed the resolve of reigning champions by putting pressure on Sussex on the third day of their County Championship Division One meeting at Edgbaston.
Jeetan Patel made an unbeaten 78 towards a Warwickshire total of 394 all out and then took 2-47 as Sussex cleared their first-innings deficit of 83 and edged into a lead of 65 by closing at 148-3.
Sussex's Chris Nash gave a bat-pad catch to short leg after making 27 and opening partner Luke Wells became becalmed, adding only five runs in a dozen overs until a slog-sweep brought about his downfall for 46.
Michael Yardy injected a little urgency in the last hour but was run out by a direct throw from Maurice Chambers at cover after making 46 from 61 balls.
Warwickshire wicketkeeper Tim Ambrose joined their injured list because of a small fracture in his right thumb - understudy Pete McKay replaced him behind the stumps.
Some ingenuity will now be required if Sussex are going to conjure up a win that could give them a say in the title race.
This match became difficult for them on the second day when Laurie Evans was dropped before he was even halfway towards making 137 and frustration levels rocketed as they took three hours to dig out the last four wickets.
The excellent Steve Magoffin removed Keith Barker almost straight away, Ben Brown taking a routine catch behind the wicket, but again they let slip a chance when Tom Milnes was missed by Brown off a sharp delivery from Chris Jordan.
The 20-year-old all-rounder went on to set a championship-best score against Sussex for the second time this season, improving by six runs on the 42 he made at Hove in May.
When he was finally out, prodding forward and nudging Nash to slip, Warwickshire had scored 141 runs while he was batting and worse was to come for Sussex as the last two wickets produced 69 from 21 overs.
Loan signing Chambers had reached double figures only six times in 37 championship matches for Essex and yet he defended sensibly for 45 minutes while the ever-positive Patel moved on to his fourth half-century in six innings.
Magoffin eventually completed his third five-wicket return of the season when Chambers (13) edged to Jordan at slip, but championship rookie Recordo Gordon proved to be equally stubborn.
All this allowed Patel to turn the screw as he hit nine fours and a six before leg spinner Will Beer secured a belated success when Brown held a chance from Gordon (10).