Worcestershire 87 for 0 (Libby 42*, Pollock 36*) trail Sussex 220 (Carson 58, Coles 54, Hudson-Prentice 51, Leach 4-37) by 133 runs
Joe Leach took his 400th first-class wicket as Worcestershire dominated Sussex on day one at Hove to keep their slim promotion hopes alive in the LV= Insurance County Championship.
The Pears realistically need to win all three remaining Division Two games and put themselves in a strong position after dismissing Sussex for 220, with Leach claiming four for 37.
That modest total represented a recovery by Sussex who had been 23 for five before half-centuries by Fynn Hudson-Prentice, James Coles and Jack Carson revived them.
But the pitch held few terrors for Worcestershire's openers Ed Pollock and Jake Libby who posted 87 without loss before bad light ended play six overs early.
After the teams observed a minute's silence in memory of Queen Elizabeth II, Leach settled into a probing line to the four left-handers at the top of the Sussex innings, taking three for 16 in his seven-over new-ball spell to leave Sussex in tatters after they had won the toss.
Ali Orr played on to his Leach's fifth ball and he pinned Tom Alsop lbw with the second delivery of his second over, a fullish delivery that swung back just enough. A similar length accounted for Tom Clark in Leach's fourth over as the batsman played across the line.
Dillon Pennington struck with his first ball when he extracted some extra bounce and Oli Carter touched it tamely to the wicketkeeper. Tom Haines, returning from a broken hand, faced 36 balls and batted for 63 minutes for his two runs but the Sussex captain played on to Ben Gibbon's second ball.
But as is so often the case at Hove, batting gets easier once the new ball loses its hardness and Hudson-Prentice, Coles and Carson led the recovery.
Hudson-Prentice was dropped at second slip by Jack Haynes on 36 but added 76 with Coles, counterattacking effectively until Pennington found just enough seam movement to have him caught behind for 51 (64 balls, 7 fours) just after lunch.
Leach returned and reached his milestone courtesy of a smart low catch by Hayes off Pakistan all-rounder Faheem Ashraf, who has joined Sussex for their last three Championship matches of the season. His side were back in trouble at 106 for seven.
But Sussex's last three wickets more than doubled the score, the fightback led by Coles and Carson, who was playing his first match of the season after recovering from knee surgery.
Coles progressed to his second half-century of the season, made in a shade under three hours. At the other end Carson was more aggressive as they added 87 in 18 overs. Coles had just reached his second half-century of the season when Pennington dropped short, and he picked out Azhar Ali on the deep backward square boundary for 54 (132 balls, 9 fours).
After Henry Crocombe holed out to mid-off, Carson was last out for 58 (74 balls, 9 fours) when he was run out by Libby's direct hit coming back for a second run.
Ashraf has been brought in to bolster a seam attack without Ari Karvelas and Steve Finn, who are out for the rest of the season but both he and the rest of the Sussex seamers struggled to break through.
Pollock gave one chance on 34 but was dropped at slip by Tom Alsop off Haines to confirm it was Worcestershire's day.
